September Challenge 2017
Chef and Pick Digit, Minimum Good Permutation, Little Chef and Sums
October Lunchtime 2017
Buggy Calculator, Maximum Number
February Challenge 2018
Chef And His Characters, Chef And The Patents, Permutation and Palindrome
December Challenge 2018 Division 2
Max and Electrical Panel, Chef and Interactive XOR, Chef and Meatballs, Chef and Interactive Contests, Chef and An Ideal Problem
November Challenge 2018 Division 2
Chef and Ridges, Chef and Happiness, Chef and Difficult Contests
January Challenge 2019 Division 2
Yet Another Problem About Sequences, Different Neighbours, Lucky Number Game, Distinct Pairs, Chef and Modulo Game, Fancy Quotes
February Challenge 2019 Division 2
Manhattan Rectangle, Guess It Right, Chef and Magical Jars, Chef and Secret Ingredients, Appy and Contest, Art of Balance, Deputy Chef
India