Serial Problem Name Difficulty Level 1. Presents 1 2. Nearly Lucky Number 1 3. Petya and Strings 1 4. Tram 1 5. Ultra-Fast Mathematician 1 6. Amusing Joke 1 7. Way Too Long Words 1 8. Xenia and Ringroad 2 9. Slightly Decreasing Permutations 2 10. Football 2 11. Caisa and Pylons 2 12. Present from Lena 2 13. k-String 2 14. Fancy Fence 2 15. Chat room 2 16. Contest 2 17. Twins 2 18. Puzzles 2 19. String Task 2 20. Mashmokh and ACM 3 21. The Child and Toy 3 22. Fence 3 23. T-primes 3 24. Rank List 3 25. Fox and Box Accumulation 3 26. Cinema Line 3 27. Escape from Stones 3 28. Laptops 3 29. Little Elephant and Bits 3 30. Flipping Game 3 31. Dima and Staircase 3 32. Building Permutation 3 33. Ilya and Queries 3 34. Kuriyama Mirai's Stones 3 35. Party 3 36. Ice Skating 3 37. Cut Ribbon 3 38. Booking System 4 39. Fox And Names 4 40. Fox And Two Dots 4 41. Pocket Book 4 42. Array 4 43. Ladder 4 44. Divisibility by Eight 4 45. Little Elephant and Problem 4 46. Ciel and Flowers 4 47. Convex Shape 4 48. Maze 4 49. View Angle 4 50. Mr. Kitayuta, the Treasure Hunter 4 51. Maximum Absurdity 4 52. Color Stripe 4 53. Checkposts 4 54. Misha and Forest 4 55. Kolya and Tandem Repeat 4 56. Anya and Ghosts 4 57. Removing Columns 4 58. Beautiful Numbers 4 59. Vasya and Chess 4 60. Hamburgers 4 61. Colorful Graph 4 62. To Add or Not to Add 4 63. Xenia and Bit Operations 4 64. Little Girl and Maximum XOR 4 65. Arithmetic Progression 4 66. Friends and Presents 4 67. Barcode 4 68. Xenia and Weights 4 69. Little Dima and Equation 4 70. Long Jumps 4 71. Tetrahedron 4 72. Physics Practical 4 73. Boredom 4 74. Valera and Elections 4 75. Little Girl and Maximum Sum 4 76. George and Job 4 77. Table Decorations 4 78. k-Tree 4 79. Color the Fence 4 80. Polo the Penguin and Matrix 4 81. Another Problem on Strings 4 82. Exams 4 83. Caesar's Legions 4 84. Beautiful Sets of Points 4 85. Number of Ways 4 86. A and B and Interesting Substrings 5 87. Valid Sets 5 88. Devu and Partitioning of the Array 5 89. Good Substrings 5 90. Wonder Room 5 91. Present 5 92. Painting Fence 5 93. Vasya and Basketball 5 94. Bear and Prime Numbers 5 95. Restore Graph 5 96. Gargari and Bishops 5 97. Multiplication Table 5