The official solution for G is wrong: it overflows signed 64-bit integer.

This is shown by these submissions: https://codeforces.me/contest/2241/submission/380753097 https://codeforces.me/contest/2241/submission/380758313

i mean Solution verdict: OK

Checker: ok 1 number(s): "-8491303560709551616"

is not okay, check my hacks.

"Recently, your account was used to crawl. Please change your password to prevent your account from being used for unauthorized activities." is very stupid. I can't even hack.