Codeforces Round #300 (with prizes!) Hello, Codeforces! [On Sunday, April 26th at 19:00 MSK](http://www.timeanddate.com/worldclock/fixedtime.html?day=26&month=4&year=2015&hour=19&min=0&sec=0&p1=166) the 300'th regular Codeforces Round will take place. I would like to congratulate all Codeforces members and administration on this remarkable milestone. The platform has grown hugely in size and quality since its foundation, has hosted lots of exciting competitions, and has been providing the opportunity to everyone to hone their problem solving and algorithmic mastery. For this we thank the Codeforces platform creator [user:MikeMirzayanov,2015-04-24] and all the Codeforces crew. Keep up the incredible job, guys! That being said, I'm excited to announce that the problems on the jubilee three-hundredth Codeforces Round will be set by me, Mikhail Tikhomirov ([user:Endagorion,2015-04-24]). You may remember the past rounds with my problems: [#99](http://codeforces.com/contests/138,139), [#109](http://codeforces.com/contest...

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Codeforces Round #270 Do you want to win a T-shirt? Do you want to learn how to design tasks for programming contest? Do you want to solve 7 tasks in 2.5 hours? So Codeforces Round #270 is right for you. It was designed by me in California, Assembled in polygon (so Thank you [user:MikeMirzayanov,2014-09-26] for the system and [user:Gerald,2014-09-26] for organize and testing), will start on [regular time this Sunday](http://www.timeanddate.com/worldclock/fixedtime.html?day=28&month=9&year=2014&hour=19&min=30&sec=0&p1=166), don't miss it! The organizers of **<a href="/blog/entry/13929">Marathon24</a>** decided to present gifts to the best finishers of the round! Best 25 participants will get Marathon24 tshirts! Thanks! <center> <img src="http://www.elmostshirts.com/images/tshirts.jpg"/> <br><small>It is just an image to attract your attention. Real tshirts will be designed specially for Marathon24!</small> </center> There are some articles introduced how to become a problem setter, like [Pro...

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CodeCraft-21 and Codeforces Round #711 (Div. 2) Hello all! We are proud to invite you to **CodeCraft-21**, which takes place on [contest_time:1498]. It is rated for all Div2 participants (rating under 2100). This contest comes under **Threads'21**, as a part of our annual techno-cultural fest [Felicity, IIIT Hyderabad](https://felicity.iiit.ac.in). We have **special prizes for Indian participants**! <img src="/predownloaded/8e/0a/8e0a76faf6acc96ba6ffb9b873136259066b5211.png" width="450px"> You will be given **six problems** to solve in a duration of **two hours**. We have tried our best to keep clean statements, useful samples with good explanations, and strong pretests! We have written step-wise editorials, and will also release video editorials! We would like to thank these amazing people for helping make the contest happen: - [user:bleddest,2021-03-27] for great coordination of our round - [user:ninja_28,2021-03-27], [user:dixitgarg,2021-03-27], [user:ltc.groverkss,2021-03-27] and myself for amazing problem...

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Bayan Contest Warm Up round + 50 tshirts! <img src="http://bayanbox.ir/id/2486223970916195531?view" style="width: 40%; float: right;"> - Bayan **warm-up** round will be held on Sunday, [October 5th 2014, 13:00 (UTC)](http://www.timeanddate.com/worldclock/fixedtime.html?day=5&month=10&year=2014&hour=13&min=00&sec=0) and as indicated before, it will be held on Codeforces. Warm-up round is not a required round but top 50 are going to win t-shirts and it is going to be rated for both divisions. - Problems have been prepared by [user:mruxim,2014-10-02], [user:mR.ilchi,2014-10-02], [user:havaliza,2014-10-02] . We have tried our best to make the problem-set interesting and competitive and we hope you enjoy it. - It is necessary to have a complete profile on [contest.bayan.ir](http://contest.bayan.ir/en/) before the warm-up round! And please do make sure you have selected the correct t-shirt size! - We have upgraded our contest platform, and we've made sure everything is stable, tuned and robust now. Thanks to all those ...

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Introduction to DP with Bitmasking Hello Codeforces! This series of videos are focused on explaining dynamic programming by illustrating the application of DP with bitmasking through the use of selected problems from platforms like Codeforces, Codechef, SPOJ, CSES and Atcoder. After going through this series, you should find yourself confident in solving problems which require the use of dp and bitmasks and also implementing them in a reasonable amount of time. I will also live code and submit the solutions to the problem on the coding platform from where the problem comes. Some Basic elements of Dynamic Programming ------------------ Some general ideas and my thoughts about DP to help you get started:<br> Part 1: [https://youtu.be/24hk2qW_BCU](https://youtu.be/24hk2qW_BCU)<br> 1. What is Divide and Conquer?<br> 2. What is Dynamic Programming?<br> 3. Types of DP problems.<br> Part 2: [https://youtu.be/yfgKw6BUZUk](https://youtu.be/yfgKw6BUZUk)<br> 1. What is a DP-state?<br> 2. Characterizing ...

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Divide by Zero 2018 and Codeforces Round #474 (Div. 1 + Div. 2, combined) Hi Codeforces! [Programming Club, IIT Indore](https://pclubiiti.github.io/) and [Euristica 2018](https://euristica.in/) are proud to present our flagship event, **Divide By Zero!** The contest will take place on [Saturday, 7th April at 9:35PM IST](https://www.timeanddate.com/worldclock/fixedtime.html?day=7&month=4&year=2018&hour=19&min=5&sec=0&p1=166).  **Prizes :** Codeforces T-shirts for top 15 participants overall and top 15 participants in India. Thanks to the following people for making the round possible : - [user:apoorv_kulsh,2018-04-06], [user:arnabsamanta,2018-04-06], [user:AakashHanda,2018-04-06], [user:vicennial,2018-04-06], [user:kr_abhinav,2018-04-06], [user:decrypt.cp,2018-04-06], [user:rohitranjan017,2018-04-06] and myself for setting the problems. - [user:usaxena95,2018-04-06] and [user:killer_bee,2018-04-06] for their help with the problems. - [user:300iq,2018-04-07] and [user:demon1999,2018-04-07] for testin...

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Invitation to Spybits CP Contest, Udyam'22 — IIT(BHU) Varanasi Hello Everyone!<br> We would like to invite you all to participate in the [SPYBITS2022 CONTEST-2](https://www.codechef.com/SPY22022) aka the Spybits CP Contest, under the banner of Udyam'22, IIT (BHU) Varanasi. The contest will be held on [5th April 2022 at 19:05 IST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=SPYBITS+2022+CONTEST-2&iso=20220405T1905&p1=176&ah=2&am=30). Udyam is the annual technical fest of the Department of Electronics Engineering, Indian Institute of Technology (BHU),Varanasi. To know more about Udyam, please visit the official website of [Udyam'22](https://www.udyamfest.com/). We would like to thank our Title Sponsor, Cisco and Event Sponsor, Nullcon. Spybits CP Contest is the second round of the SPYBITS event, in which your algorithmic problem solving skills are tested. This contest is open to everyone, so you can appear in the contest even if you haven't registered for the SPYBITS event. All the problems have been prepared by [user:X...

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HackerRank World Codesprint Hello CodeForces Community! I am glad to share that HackerRank's [World Codesprint](https://www.hackerrank.com/worldcodesprint) is scheduled on [29-January-2016 at 17:00 UTC](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Hackerrank+World+Codesprint&iso=20160129T17&p1=1440). Contest duration is 24 hours. Go ahead and [register now](https://www.hackerrank.com/worldcodesprint) to show off your coding abilities, and win upto $2000 Amazon gift cards/bitcoins, medals and tshirts. [Note: Winners from US and India will receive Amazon Gift Cards. Winners from other countries will receive equivalent USD amount in bitcoins.] The contest is sponsored by Distil-networks, Pampared-chef and Philips. Contest site will be continually updated to reflect upcoming sponsors. The problems were prepared by [user:malcolm,2016-01-27],[user:Errichto,2016-01-27],[user:svanidz1,2016-01-27], [user:forthright48,2016-01-27], and [user:Shafaet,2016-01-27]. Thanks to [user:wanbo,2016-01-27] f...

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HackerRank HourRank — 11 Hello everyone! I am glad to invite you to the 11th edition of [HourRank](https://www.hackerrank.com/contests/hourrank-11/challenges). The contest starts on August 2nd 16:30 UTC [(View local time)](http://www.timeanddate.com/worldclock/fixedtime.html?msg=HackerRank+HourRank+11&iso=20160802T1630&p1=%3A&ah=1). HourRank is a super short one hour long algorithmic contest. This time we will have 3 challenges, created by me, [user:_shil,2016-08-01] and [user:forthright48,2016-08-01]. As always, thanks to [user:wanbo,2016-08-01] for testing the challenges and thanks to [user:pkacprzak,2016-08-01] for helping with editorials. There are **subtasks** in each of the problems, so I strongly encourage you to read all the problems. Participants are ranked by score. If two participants have the same score, the one who reached the score first, wins. Top-10 contestants will get a HackerRank Tshirt. In the last round no one was able to get perfect score (though all the problems were s...

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July Easy'17 HackerEarth Hi everyone! I would like to invite you to participate in [July Easy](https://www.hackerearth.com/challenge/competitive/july-easy-17/) at HackerEarth. The contest is scheduled to start at [1st July, 2200 hrs IST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=July+Easy%2717+HackerEarth&iso=20170701T22&p1=438&ah=3). There will be six tasks in the problemset, for beginners in competitive coding. This contest is a Rated contest and open for all. I hope that everyone from beginners to experienced contestants will be able to find some problem that challenges and interests them. [user:bk2dcradle,2017-06-30] and [user:arjundabra,2017-06-30] are the authors of this problemset. The testing was done by me([user:harshil,2017-06-30]). Editorials have been written by [user:horcrux,2017-06-30]. As always, [user:r3gz3n,2017-04-22] was a great help, and I would like to thank him for taking care of all the technical aspects of contest preparation. While problem solving ...

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HackerRank World Codesprint May Hello CodeForces Community! HackerRank is back with another [World Codesprint](https://www.hackerrank.com/contests/may-world-codesprint/challenges)! Join us on 21st May, exact time [can be found here](http://www.timeanddate.com/worldclock/fixedtime.html?msg=HackerRank+World+Codesprint&iso=20160521T16&p1=%3A). Its your chance to win upto $2000 Amazon gift cards/bitcoins and tshirts. [Note: Winners from US and India will receive Amazon Gift Cards. Winners from other countries will receive equivalent USD amount in bitcoins.]. Contest duration is 24 hours. The contest will be rated. If two person gets same score, the person who reached the score first will be ranked higher. The challenges were prepared by [user:osmanorhan,2016-05-19], [user:muratt,2016-05-19], [user:ma5termind,2016-05-19], [user:forthright48,2016-05-19], [user:cherrytree,2016-05-19]. I would like to thank [user:wanbo,2016-05-19] and [user:malcolm,2016-05-19] for helping to prepare this round. Editorials ...

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HackerRank World Codesprint April Hello CodeForces Community! I am glad to share that HackerRank's [World Codesprint April](https://www.hackerrank.com/world-codesprint-april) is scheduled on [29-April-2016 at 16:00 UTC](http://www.timeanddate.com/worldclock/fixedtime.html?msg=World+Codesprint+April&iso=20160429T16&p1=%3A). Contest duration is 24 hours. Go ahead and [register now](https://www.hackerrank.com/worldcodesprint) to show off your coding abilities, and win upto $2000 Amazon gift cards/bitcoins and tshirts. [Note: Winners from US and India will receive Amazon Gift Cards. Winners from other countries will receive equivalent USD amount in bitcoins.] The problems were prepared by [user:malcolm,2016-04-28], [user:stonefeang,2016-04-28], [user:svanidz1,2016-01-27], [user:ma5termind,2016-04-28] and [user:shafaet,2016-04-28]. Thanks to [user:wanbo,2016-04-28] for testing the problems and [user:forthright48,2016-04-28] for helping with editorials. The contest will be rated. If two person gets same score,...

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Let's have some fun — November Easy'15 on HackerEarth Hello Codeforces! [November Easy](https://www.hackerearth.com/november-easy-15/) is taking place on November the 1-st at [19:00 MSK](http://www.timeanddate.com/worldclock/fixedtime.html?msg=November%20Easy%20%2715&iso=2015-11-01T10:00:00&p1=64). Contest duration is 3 hours. The contest will consist of 6 problems. Each problem is worth 100 points. Most of them have partial scoring. Ties are resolved by penalty time. I've decided to experiment a bit, so the format of the contest will slightly **differ** from the previous ones. There will be: - **4** usual algorithm problems of various difficulty. In my opinion they might be interesting for complete beginners as well as for enough experienced participants. - **2** problems that differ from usual ACM / IOI tasks. I'd like to thank all the guys who worked on it with me: admins [user:belowthebelt,2015-10-30], [user:chandan111,2015-10-30], tester [user:kmcode,2015-10-30] and editorialist [user:pkacprzak,2015-10-30]. Yo...

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Invitation to HackerEarth March Easy'17 Hello Codeforces Community, [HackerEarth March Easy'17](https://www.hackerearth.com/challenge/competitive/march-easy-17/) will start at [9:30 PM IST on 1st March](https://www.timeanddate.com/worldclock/fixedtime.html?msg=HackerEarth+March+Easy%2717&iso=20170301T2130&p1=438&ah=3). The contest is of 3 hours. It will be a rated contest and is open for everyone. There will be 6 algorithmic problems of various difficulty level. Problems are prepared by me ([user:vaibhavjaimini,2017-02-27]). They have been thoroughly tested by [user:usaxena95,2017-02-27] and editorials are prepared by [user:r3gz3n,2017-02-27]. Thanks to [user:belowthebelt,2017-02-27] and [user:r3gz3n,2017-02-27] for their help in preparing this contest and to [user:_AJ_,2017-02-27] for his feedback on problems. This is the first time I am preparing a contest, so it'll be great to have some feedback. **Prizes:** Top 5 beginners (1st year or 2nd year) will receive HackerEarth Tshirts. Hope you'll enjoy the pro...

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[HackerRank] CodeStorm on 29th October / Awesome Prizes Hello CodeForces Community! I am glad to share that HackerRank's [CodeStorm](http://www.hackerrank.com/codestorm) (CodeSprint on Algorithmic Programming Challenges) is scheduled on 29-October-2015 at [16:00 UTC](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Codestorm&iso=20151029T16&p1=%3A). Contest duration is 24 hours. Go ahead and [register now](http://www.hackerrank.com/codestorm) to show off your coding chops, and win amazing prizes like GoPro HERO4 camera, Bose Speakers, FitBit Charge, HackerRank hoodies and t-shirts. All participants who completely solve one challenge will get $100 of AWS credits. Also, you'll get an opportunity to connect for a career opportunity with CodeStorm contest sponsors &mdash; like ErosDigital, Indeed Prime, Slice, Steelhouse, Sightline Systems, SWATT etc. Contest site will be continually updated to reflect upcoming sponsors. The problems were created by [user:malcolm,2015-10-19], [user:svanidz1,2015-10-19], [user:Timur_Sitdikov,...

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Invitation to ASN_Epoch 1.0 ASN — Algorithm Society of NSIT, are proud to announce the ASN Epoch1.0!  It will be a Short contest consisting of 5 problems with all problems visible from the start and no hacks. Its a 3 hour contest with 5 problems. Details ============= Contest Date : 19th February 2016 Time : 2130 to 0030 IST Programming Partner : Codechef Contest Link : [CodeChef](https://www.codechef.com/ASNE2016) Prizes ====== - There are cash prizes worth ₹ 5,000 for top 3 NSITians. - Top 10 Global competitors will be awarded CodeChef Tshirts too. The problems in the contest are prepared by [user:anh1l1ator,2016-02-18] , [user:notiitian,2016-02-18] and [user:Red_some_day,2016-02-18]. Special thanks to [user:Code_destroyer,2016-02-18] , [user:sandeep_2795,2016-02-18] and Mayank Hooda for their help. For more details / contact details, visit: - Our Facebook Event [Page](ht...

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Qualification round — Bayan programming Contest 2014-2015  In a few hours, Bayan Qualification round begins. Qualification round will be held as our first official and required round of [Bayan Programming Contest 2014-2015](http://contest.bayan.ir/en/). It will begin on [October 9th, 06:00 (UTC)](http://www.timeanddate.com/worldclock/fixedtime.html?day=9&month=10&year=2014&hour=6&min=00&sec=0) for a **72-hour** period, and solving only one problem is enough to advance you to the elimination round. This round is going to be an **easy event** with 3 very easy problems and 5 random participants will be receiving **t-shirts**. Whether you are testing your luck for a random tshirt or are aiming for one of 100 tshirts of elimination round, or even if you are already planning for your trip to Tehran, you should not miss the qualification round. ([contest.bayan.ir](http://contest.bayan.ir/en/)) Please do make sure that you have fully read the main contest [announcement](htt...

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Codeforces на сборах в Петрозаводске 2011 (лето) <img src="http://assets.codeforces.com/images/codeforces-tshirt-want-problems-forw.png" style="float:right;margin:0.25em 1em;width:280px;"> <p> Всем привет! </p> <p> Не знаю как другие делегации, но две команды Саратовского государственного университета и Дмитрий Матов в качестве тренера сегодня отправились в славный город Петрозаводск. К сожалению, в этот раз у меня нет возможности посетить столь уважаемое мероприятие, но мыслями я буду на берегу Онеги и, конечно, буду болеть за свои команды! </p> <p> В этот раз команда Codeforces решила отметиться на сборах раздачей футболок, благо успешный опыт уже был. Итак, 29-го августа в 20:00 (московское время) состоится Codeforces Beta Round #84. Лучшие 50 выступивших из числа тренеров команд и участников Петрозаводских сборов получат по фирменной футболке Codeforces! Конечно, речь идет о первом дивизионе :) </p> <p> Для того чтобы участвовать в розыгрыше, до начала раунда необходимо убедиться, что в вашем профиле присутствует...

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ACM-ICPC NEERC celebrates its 15th anniversary <img src="http://assets.codeforces.com/images/neerc-15-en.png" style="margin:0 1em;float:left;width:170px;"> <p> This year the ACM-ICPC regional contest of our region celebrates its 15th anniversary! We heartily congratulate the organizers, members of the jury and the technical committee. We would like to give our special congratulations to the Competition Director Vladimir G. Parfenov. Thank you very much for your work not only in organizing this competition, but also in developing the programming community throughout our region. Much has been done over 15 years. All the achievements of our region teams on the ACM-ICPC finals are also due to you. I have to say that NEERC is organized on the top level and has highly interesting sets of problems which all the participants find very exciting. We wish you new successes and new achievements! </p> <a href="http://assets.codeforces.com/images/codeforces-tshirts-on-neerc.png" rel="photobox" style="margin:0 1em;float:right;"> <img src="ht...

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April Hack 101 + 800$ + Cool Tshirts + Awesome Problem Set Hi Codeforces !!! I am glad to announce HackerRank 101 Hack &mdash; 36th Edition. The contest will be held on [16:30 UTC Wednesday, April 20 2016](http://w...content-available-to-author-only...e.com/worldclock/fixedtime.html?msg=HackerRank+101+Hack-36th+Edition&iso=20160420T22&p1=54&ah=2). Contestants will be given 5 problems and 2 hours to solve them. You can sign up for the contest [here](https://www.hackerrank.com/101hack36).The prizes for this contest are:<br> First Place: $300 Amazon Gift Card <br> Second Place: $200 Amazon Gift Card<br> Third Place: $100 Amazon Gift Card <br> Fourth Place: $50 Amazon Gift Card <br> Fifth Place: $50 Amazon Gift Card <br> <br> Coders ranked 6-20: HackerRank T-shirt This contest is rated for all users. 101 Hack problem set is prepared by me ([user:_shil,2016-04-19]) and [user:ma5termind,2016-04-19] is tested by [user:wanbo,2016-04-19]. I would like to thank HackerRank for helping us hosting and preparing this round. I am sur...

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HackerRank HourRank — 8 Hi, I would like to invite you to take part in HackerRank [HourRank-8](https://www.hackerrank.com/hourrank-8) on [2nd May](http://www.timeanddate.com/worldclock/fixedtime.html?msg=HourRank+-+8&iso=20160502T16&p1=%3A&ah=1). HourRank is an one hour long programming competition. In this round, there will be only 3 problems. We tried to make it interesting for both beginners and experts. The authors of this round are [user:tunyash,2016-04-30], [user:forthright48,2016-04-30] and me. Thanks for [user:wanbo,2016-04-30] for testing the problems. Top-10 will get a nice HackerRank Tshirt! Happy Coding! Update: Score of the problems are **25-50-75**. Update: The contest has ended, congrats to the winners.  Special congrats to [user:uwi,2016-05-02] for solving all the problems.

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Second edition of Yandex.Algorithm 2015 Round 2 Second edition of Round 2 will start at [08:00 on June 13, 2015 MSK](http://timeanddate.com/worldclock/fixedtime.html?year=2015&month=6&day=13&hour=08&min=0&sec=0&p1=166). Don't miss your chance to win a tshirt and advance to the final round. The round is made by [user:GlebsHP,2015-06-11], he even promises to share the problem analysis right after the end of the round. What a nice reason to wake up early on this Saturday! UPD: The round is right around the corner!

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Topcoder Tshirts I was the lucky one to win the T-shirt of the lucky draw of **SRM-528**.I contacted topcoder services team and they told me that they had released it on 6th Jan 2012 and that the t-shirt would come to me within 10 weeks.But I have not received it till now...Could anyone tell me as to : 1) how will it reach me??(eg- registered post,courier ,or some contracted person etc.) 2)How do I claim for it??(For eg it comes through post then I have to show some docket number or some other document to claim it directly from the post office )Then how do I claim it?? I am an **Indian Citizen**...Apart from this ,I am also due for the **NASA USPTO challenge** T-shirt and the **Accenture Mobile Survey** T-shirt from topcoder...I wrote this in the topcoder forum but got no reply and I dont want to lose my special gifts ...Someone Please help???

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Didn't receive Google CodeJam t-shirt Hi, I haven't received google code jam tshirt yet. My friends have received them. I tried mailing [email protected] but didn't get any reply.

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Google CodeJam 2021 T-Shirt So by some miracle, I qualified for Round 3 of Codejam. This meant I would be getting a CodeJam T-Shirt. However, yesterday everyone I know got emails to claim their t-shirts but I did not :( . Can anyone in the cf community help me out? I was very excited to get the tshirt. Does anyone know other people who have faced the same issue? Edit : I emailed them yesterday itself but did not receive a reply :/

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Free t-shirt Got this message for free tshirt from "cfadministration" 

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Need help to solve this problem I am quite weak in DP and Bitmasking concept. I need help to solve this problem https://www.codechef.com/problems/TSHIRTS Thanks.

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Fraud in Kotlin roumds Hello codeforces system From jetbrains, I won a tshirt in kotlin round 7, and its now more than 6 months but i dont receive any tshirt till now, please let me know is that a technical problem or thats a fraud from there side. If thats a fraud if you told i will complain against them in government of india portal.

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