January Challenge 2019 Division 2
Fancy Quotes, Lucky Number Game
February Challenge 2019 Division 2
Manhattan Rectangle, Guess It Right, Chef and Magical Jars, Chef and Secret Ingredients, Appy and Contest, (Challenge) Chef with Orchestra in the Kitchen, Art of Balance, Deputy Chef
March Challenge 2019 Division 2
Chef and Number Game, (Challenge) Interleaving Strings, Chef and a Beautiful Digit, Yet Again a Subarray Problem, Cheating on Queue, Chef got Recipes, Chef and Soccer
April Challenge 2019 Division 1
Offer for Chef, Playing with Numbers, Subtree Removal
July Challenge 2019 Division 1
Guess the Prime!, Parity Again, Minimum and Maximum, Chef and Mean
July Challenge 2020 Division 1
Chefina and Swaps, Missing a Point, Doctor Chef
Russia