Index Problem Difficulty Solved 1 Green and Black Tea 1500 2 Stas and the Queue at the Buffet 1500 3 Bishwock 1500 4 Secret Passwords 1500 5 Lunar New Year and a Wander 1500 6 Make a Permutation! 1500 7 Vus the Cossack and Numbers 1600 8 Alena And The Heater 1600 9 Love Rescue 1600 10 Extra Element 1700 11 Ticket Game 1700 12 Slime 1700 13 Artsem and Saunders 1700 14 Substring 1700 15 Harmonious Graph 1700 16 Alarm Clock 1700 17 Dasha and Very Difficult Problem 1700 18 Cow and Snacks 1700 19 Valid BFS? 1700 20 Glider 1700 21 Array Restoration 1700 22 Paint the Tree 1700 23 Petya and Array 1800 24 Cloud of Hashtags 1800 25 Chloe and pleasant prizes 1800 26 Fun with Integers 1800 27 My pretty girl Noora 1800 28 Let's Play the Words? 1800 29 Shovel Sale 1800 30 Serval and Rooted Tree 1800 31 Nastya Is Buying Lunch 1800 32 Treasure Island 1800 33 Robot Vacuum Cleaner 1800 34 The Wu 1900 35 Flood Fill 1900 36 Olya and Energy Drinks 1900 37 Misha, Grisha and Underground 1900 38 Ability To Convert 1900 39 Alex and Julian 1900 40 Restore Permutation 1900 41 White Lines 1900 42 Social Circles 1900 43 Shichikuji and Power Grid 1900 44 Ehab and the Expected XOR Problem 1900 45 Bash and a Tough Math Puzzle 1900 46 Kilani and the Game 1900 47 Fafa and Ancient Alphabet 1900 48 Shark 1900 49 The Door Problem 2000 50 Vladik and Favorite Game 2000 51 Mahmoud and Ehab and another array construction task 2000 52 Neko and Aki's Prank 2000 53 An overnight dance in discotheque 2000 54 Mahmoud and Ehab and the binary string 2000 55 Treasure Hunting 2000 56 TV Shows 2000 57 Mahmoud and a Dictionary 2000 58 Leaving Auction 2000 59 Ehab and another another xor problem 2000 60 Gourmet choice 2000 61 Olya and magical square 2000 62 Fedor and coupons 2000 63 Field expansion 2000 64 Jon and Orbs 2100 65 Irrigation 2100 66 Portals 2100 67 Perfect Groups 2100 68 Unusual Sequences 2100 69 Fishes 2100 70 Alice and the Doll 2100 71 Vitya and Strange Lesson 2100 72 Colorful Points 2100 73 Police Stations 2100 74 Full Binary Tree Queries 2100 75 Cute Sequences 2100 76 Huge Strings 2100 77 Okabe and City 2200 78 Kuro and GCD and XOR and SUM 2200 79 Tree 2200 80 Anton and School - 2 2200 81 Nature Reserve 2200 82 Felicity's Big Secret Revealed 2200 83 Winter is here 2200 84 Sonya and Matrix 2200 85 Mysterious Code 2200 86 Steps to One 2300 87 Enchanted Artifact 2300 88 Ralph And His Tour in Binary Country 2300 89 String Mark 2300 90 Mike and distribution 2300 91 Labelling Cities 2400 92 Dasha and Chess 2400 93 Destroy the Colony 2500 94 A Shade of Moonlight 2500 95 Ratings and Reality Shows 2500 96 Complete Mirror 2500 97 Jamie and To-do List 2600 98 Scissors 2700 99 Sagheer and Kindergarten 2700 100 The Overdosing Ubiquity 2800