December Challenge 2018 Division 2
Chef and Interactive Contests, Max and Electrical Panel, Chef and An Ideal Problem
November Challenge 2018 Division 2
Chef and Ridges, Chef and Difficult Contests
October Challenge 2018 Division 2
Chef and Serves, Byte to Bit
February Challenge 2019 Division 2
Chef and Magical Jars, Chef and Secret Ingredients, Appy and Contest, Deputy Chef
March Challenge 2019 Division 2
Chef and a Beautiful Digit, Chef and Number Game
April Challenge 2019 Division 2
Friend or Girlfriend, Maximum Remaining
October Challenge 2019 Division 2
Array Modification, Operations on a Matrix, Phone Prices
November Challenge 2019 Division 2
Hard Sequence, Weapon Value
December Challenge 2019 Division 2
That Is My Score!, Plus Multiply
February Challenge 2020 Division 2
No Change Required, The Theatre Problem, School of Geometry, Hard Cash, (Challenge) Raisins, Long Contest and Cook Off Overlaps
December Challenge 2020 Division 2
Vaccine Production, Vaccine Distribution, Even Pair Sum, Positive Prefixes
February Challenge 2021 Division 3
Chef and Meetings, Maximise Function, Highest Divisor
March Challenge 2021 Division 3
Chef and Groups, Space Arrays, No Time to Wait
April Challenge 2021 Division 3
Valid Pair, World Record, Strong Language
Serbia