August Long Challenge 2017
Chef And Fibonacci Array, Chef and Mover, Palindromic Game, Mathison and the Data Warehouse (Challenge), Greedy Candidates, Strings and Graphs, Chef and Rainbow Array
September Challenge 2017
Minimum Good Permutation, Little Chef and Sums, Fill The Matrix, Weasel does Xor on Tree, Chef and Pick Digit, Sereja and Commands
October Challenge 2017
Chef and a great voluntary Program, Max Mex, Counter Test For CHEFSUM, A Balanced Contest
November Challenge 2017
Chef Hates Palindromes, Villages and Tribes, Periodic Palindrome Construction, Chef goes Left Right Left
March Challenge 2018 DIV 1
Pishty and Triangles, Chef and Interval Painting, Chef and Easy Problem, Chef and Gcd Queries, Mix the Colors, Minions and Voting
January Cook-Off 2022 Division 2
Palindromes Not Allowed, Mean Maximization, Subsegment Divisibility , Merged LIS, Prime Graph, Erase All But One
Belarus