October Challenge 2017
Chef and a great voluntary Program, Chef and Cycled Cycles, Shooting on the array, Max Mex, Counter Test For CHEFSUM, A Balanced Contest, (Challenge) Connecting computers, Chef and Magic Arrays
November Challenge 2017
Chef Hates Palindromes, Villages and Tribes, Periodic Palindrome Construction, Lovers Gift, Chef goes Left Right Left, Chef and Subarray Queries, Polynomials, Day Schedule, Product on the segment by modulo
December Challenge 2017
Penalty Shoot-out, Chef and Hamming Distance of arrays, Chef And Easy Xor Queries, Total Diamonds, Chef and Universe, Chef And his Cake
January Challenge 2018
(Challenge) Chef and Palindromes, Killing Monsters, Killjee and k-th letter , K-Concatenation, Maximum Score, Rectangle, String Merging, Partition the numbers
February Challenge 2018
Chef And His Characters, Permutation and Palindrome, Car-pal Tunnel, Chef And The Patents
March Challenge 2018 DIV 1
Pishty and Triangles, Chef and Interval Painting, Chef Cuts Tree, Chef and Easy Problem, Chef and Gcd Queries, Mix the Colors, Minions and Voting
China