For this problem : https://codeforces.net/contest/1805/problem/C, I submitted this solution: https://codeforces.net/contest/1805/submission/215278227.

The runtime is 78 ms.

I then submitted the exact same solution with a simple comment at the top : https://codeforces.net/contest/1805/submission/215278404.

The runtime is 93 ms.

Although meaningless here, what accounts for the difference in runtime? I would understand if the difference was 1 or 2 ms off, but 15 ms off seems like a lot for two exact same solutions.