February Challenge 2015
Chef and Chain, Time to Study Graphs with Chef, Chef and Strange Formula, Chef and Strings, Let us play with rank list, Chef and Equality
March Challenge 2015
Count Substrings, Chef and Notebooks
December Challenge 2016
Train Partner, Bear and Three Colours, Our Base is Under Attack, Roses for Alexey, Edit Distance Revisited, Kirito in labyrinth, Sereja and Increasing subsequence, Kth Max Subarray
February Lunchtime 2017
Bear and House Queries, Bear and Milky Cookies
Moldova