Timed mock contest on grids, graphs, BFS/DFS, two pointers, and sliding windows, plus a modular-power problem. Each problem reads the whole contest input from standard input and prints the exact output. Read the input in your program with:
import sys
data = sys.stdin.read()
Write each answer as a complete program in your notebook, and run it with piped input, for example python my_solution.py < case.txt. Do not call input().