May Challenge 2018 Division 2
Mighty Friend, Minimum Deletions, Xor Again
June Challenge 2018 Division 2
Two Flowers, Vision, Ways to Work, Sheokand and String, Binary Shuffle, Naive Chef
October Challenge 2018 Division 2
Appy and Balloons , Chef and Circles, Byte to Bit, Chef and Serves, Chef and Surprise Chessboard, Minimize Digitsum, Beautiful Bricks
January Challenge 2019 Division 1
Yet Another Problem About Sequences, Different Neighbours, Distinct Pairs, A Pizza Slice
Vietnam