Solution Link of number C question https://youtu.be/PK27JkDUq58
Some cheater:
https://codeforces.net/contest/1822/submission/203341284
https://codeforces.net/contest/1822/submission/203341760
https://codeforces.net/contest/1822/submission/203337437
https://codeforces.net/contest/1822/submission/203339721
https://codeforces.net/contest/1822/submission/203337206
https://codeforces.net/contest/1822/submission/203338592
https://codeforces.net/contest/1822/submission/203337275
https://codeforces.net/contest/1822/submission/203337979
https://codeforces.net/contest/1822/submission/203339037
https://codeforces.net/contest/1822/submission/203340194
MikeMirzayanov take action against them.