I came up with a quite slow solution for Educational Codeforces Round 168 Problem F at the last minute of the contest, and I was unable to implement it on time.

When I tried implementing the solution after the contest, it showed a time limit exceeded verdict on codeforces. 273604133

However, when I test the exact same code and same test on atcoder with the "Custom invocation", it shows that the code only runs in 2155 ms, which is much lower than that of the TL. Can anyone help me with this issue? Thanks.