February Challenge 2017
Chef and Yoda, Eugene and big number, Primitive Queries, Interval Game, Chef and Triangles, Chef and his Best Friend, Chef and His Apartment Dues, Most Frequent Element, Gerrymander
June Challenge 2017
Xenny and Coin Rankings, Pairwise union of sets, Triplets, Chef and the Feast, A Good Set, Saboteur (Challenge), Chef and Prime Queries, Persistent oak, Cloning
March Challenge 2018 DIV 1
Mix the Colors, Minions and Voting, Chef and Gcd Queries, Chef and Easy Problem, Chef Cuts Tree, Pishty and Triangles
May Challenge 2018 Division 1
S-T Mincut, Series Sum, Change the Signs, Edges in Spanning Trees, Not a Convex Hull (Challenge), Fake Binary Search, Dibs on Fibs
China