May Challenge 2017
Chef and Sub Array , Long Sandwich , Gotham PD, Chef and his daily routine, Courses in an university, Blocked websites, Median of adjacent maximum numbers, Chef and Subsequences, Chef and Battleship
June Challenge 2017
Saboteur (Challenge), Pairwise union of sets, Triplets, Xenny and Coin Rankings, Chef and the Feast, Cloning, A Good Set, Euler Sum, Chef and Prime Queries
July Challenge 2017
Multiplication Program, IPC Trainers, Calculator , Whats in the Name, Pishty and tree, Chef and Sign Sequences, Tree Expectancy
August Long Challenge 2017
Strings and Graphs, Greedy Candidates, Palindromic Game, Hill Jumping, Chef and Mover, Chef And Fibonacci Array, Chef and Rainbow Array
September Challenge 2017
Sereja and Commands, Chef and Pick Digit, Minimum Good Permutation, Fill The Matrix, Little Chef and Sums
March Challenge 2018 DIV 1
Chef and Easy Problem, Mix the Colors
Taiwan