January Challenge 2015
Sereja and Number Division 2, Gcd Queries, One Dimensional Kingdoms, Sereja and Votes, Chef and Stones, Chef and A Large Permutation
February Challenge 2015
Chef and Chain, Chef and Strange Formula, Chef and Strings, Let us play with rank list, Jigsaw Puzzle Solving, Chef and Equality
August Challenge 2015
Gravity Guy, Cooking Machine
September Challenge 2015
Nikitosh and xor, Cracking the Code
February Challenge 2016
Chef-Detective, Rectangles of Love
June Challenge 2016
Chef And The Hiring Event, Chef And Binary Operation
August Challenge 2016
Fighting Ebola, Chef and Chocolate, Chef and Round Run, Funny gnomes
September Challenge 2016
Chef and Matrix Division, Chef and calculation, JosephLand, Faded Palindromes, Chef and digits of a number, Dividing Machine, Chef and Friends
November Challenge 2016
Count Permutations, Friends Meeting, Gift and Chef, Chef and squares, Task for Alexey
India