December Challenge 2014
XOR with Subset, Chef and Apple Trees, Sereja and GCD
March Challenge 2015
Count Substrings, Chef and Notebooks, Devu and his Class, Sign Wave
April Challenge 2015
Count Sequences, Chef and Piano Scales, Broken Telephone, Chef and Interview
May Challenge 2015
Devu and binary String, Chef and Prime Divisors, Set Difference , Chef and new recipe
June Challenge 2015
Steady tables, Chef and Polygons, Chef and Memory Limit, Chef and His Friend
July Challenge 2015
Bread, Na2a and lucky stone, Chef and Cube
April Cook-Off 2015
Equality, Version Control System
October Challenge 2016
Chef and Keyboard, Chef and Three Dogs, Chef and Two String
June Challenge 2017
Chef and Prime Queries, A Good Set, Xenny and Coin Rankings, Triplets
Poland