Hello CodeForces, today I tried solving the problem from a recent contest: 1923E - Count Paths

My Solution:

If you see any problems with the code, please let me know as I can't see the problem. If you don't understand a part of the code, please ask and I will clarify.

Submission: 255437477

UPD: The runtime takes more than 30 seconds! So I guess the runtime is O(N^2) somehow.