July Challenge 2017
Whats in the Name, Calculator , IPC Trainers, Chef and Sign Sequences
August Long Challenge 2017
Chef and Rainbow Array, Chef and Mover, Palindromic Game, Greedy Candidates
September Challenge 2017
Sereja and Commands, Chef and Pick Digit, Minimum Good Permutation, Fill The Matrix, Little Chef and Sums
December Challenge 2017
Penalty Shoot-out, Chef and Hamming Distance of arrays, Chef And his Cake, Total Diamonds
July Cook-Off 2017
Chang and Bitwise OR, Chang and the Perfect Function
September Cook-Off 2017
Statistics Construction, Subsequence Equality
October Cook-Off 2017
Chef and Counting Test, Chef and Employment Test, Chef and Weird Queries
January Challenge 2018
K-Concatenation, Maximum Score, Rectangle, String Merging, Partition the numbers
Ukraine