Problem Solving # Challenge Solution 1 102B - Sum of Digits Solution 2 112A - Petya and Strings Solution 3 1141A - Game 23 Solution 4 121A - Lucky Sum Solution 5 129A - Cookies Solution 6 129B - Students and Shoelaces Solution 7 1362B - Johnny and His Hobbies Solution 8 144A - Arrival of the General Solution 9 152B - Steps Solution 10 1543B - Customising the Track Solution 11 160B - Unlucky Ticket Solution 12 1617B - GCD Problem Solution 13 16B - Burglar and Matches Solution 14 1702A - Round Down the Price Solution 15 1702B - Polycarp Writes a String from Memory Solution 16 1702C - Train and Queries Solution 17 186B - Growing Mushrooms Solution 18 189A - Cut Ribbon Solution 19 208A - Dubstep Solution 20 215B - Olympic Medal Solution 21 219A - k-String Solution 22 221A - Little Elephant and Function Solution 23 227B - Effective Approach Solution 24 230B - Tprimes Solution 25 231A - Team Solution 26 236A - Boy or Girl Solution 27 236B - Easy Number Challenge Solution 28 262B - Roma and Changing Signs Solution 29 263A - Beautiful Matrix Solution 30 266A - Stones on the Table Solution 31 268A - Games Solution 32 270A - Fancy Fence Solution 33 313B - Ilya and Queries Solution 34 31A - Worms Evolution Solution 35 342A - Xenia and Divisors Solution 36 344A - Magnets Solution 37 352B - Jeff and Periods Solution 38 376B - IOU Solution 39 381A - Sereja and Dima Solution 40 385B - Bear and Strings Solution 41 405A - Gravity Flip Solution 42 427A - Police Recruits Solution 43 431A - Black Square Solution 44 445A - DZY Loves Chessboard Solution 45 451B - Sort the Array Solution 46 463B - Caisa and Pylons Solution 47 476B - Dreamoon and WiFi Solution 48 47B - Coins Solution 49 514B - Han Solo and Lazer Gun Solution 50 520B - Two Buttons Solution 51 535B - Tavas and SaDDas Solution 52 567A - Lineland Mail Solution 53 59A - Word Solution 54 617B - Chocolate Solution 55 677A - Vanya and Fence Solution 56 686A - Free Ice Cream Solution 57 6B - President's Office Solution 58 731A - Night at the Museum Solution 59 732A - Buy a Shovel Solution 60 734A - Anton and Danik Solution 61 770A - New Password Solution 62 787A - The Monster Solution 63 78B - Easter Eggs Solution 64 791A - Bear and Big Brother Solution 65 810B - Summer selloff Solution 66 UVA - 10106 - Product Solution 67 UVA - 10110 - Light more light Solution 68 UVA - 11565 - Simple Equations Solution