Hi, Can anyone explain why does I get Runtime error whenever I do graph problem while submitting in Python or pypy?

Problem : https://codeforces.com/contest/977/problem/E

Submission : https://codeforces.com/contest/977/submission/119559247

Ps: Same issue again, I think it because of recursion

Problem : https://codeforces.com/contest/1106/problem/D

Submission : https://codeforces.com/contest/1106/submission/119562804