September Challenge 2017
Chef and Pick Digit, Minimum Good Permutation, Fill The Matrix, Little Chef and Sums, Sereja and Commands
October Challenge 2017
Chef and Magic Arrays, Chef and a great voluntary Program, Chef and Cycled Cycles, Max Mex, Counter Test For CHEFSUM, A Balanced Contest
December Challenge 2018 Division 2
Directing Edges, Chef and An Ideal Problem, Chef and Interactive Contests, Chef and Meatballs, Chef and Interactive XOR, Max and Electrical Panel, (Challenge) Delete DAG
May Challenge 2020 Division 1
Buying a New String, Triple Sort, Chef and Bitwise Product
May Lunchtime 2020 Division 1
Absolute Min Max, Convert the String, Tree difference
June Challenge 2020 Division 1
Danya and Different Values, The Delicious Cake, The Tom and Jerry Game!, Operations on a Tuple
July Challenge 2020 Division 1
LCM Constraints, Chefina and Swaps, Chef and Dragon Dens, Missing a Point, Doctor Chef
August Challenge 2020 Division 1
Insanely Hard School Exams, Subsequence Frequency Counting, Chefina and Strange Tree, Smallest KMP, Chef and Wedding Arrangements
September Challenge 2020 Division 1
Find XOR, Ada Matrix, Divide Candies, Move the Coins - Creating Tests, Chef and Trump Cards, Chefina and Swap
June Lunchtime 2020 Division 1
Maximum AND, Gold Mining, Square Submatrices
December Challenge 2020 Division 1
Hail XOR, String Operations, Positive Prefixes, Even Pair Sum
August Challenge 2021 Division 1 (Unrated)
Special Triplets, Problem Difficulties, Olympics Ranking
Brazil