February Challenge 2017
Chef and His Apartment Dues, Chef and Triangles
March Challenge 2017
Xenny and Alternating Tasks, Bear and Extra Number
December Cook-Off 2017
Beautiful Array, Football Match
March Challenge 2018 DIV 2
Chef and Easy Problem, Minion Chef and Bananas, Minions and Voting, Chef and Glove, Mix the Colors, A Big Sale, Pishty and Triangles
April Challenge 2018 Division 2
Cutting Plants, Workers, Average of Pairs, Count Good Prefixes, Highway Crossing, Weight of Numbers
November Challenge 2018 Division 1
Appy Loves One, Good Median, Binary Strings
June Challenge 2019 Division 1
Lent Money, Chef and Ingredients, Chef and His Dish, Intersecting Paths, Sum and GCD
Vietnam