visit.py

import sys


def snail(n, m):
    dx, dy = 1, 0
    x, y = 0, 0
    arr = [[0] * m for _ in range(n)]
    for i in range(1, n * m + 1):
        print(y, x)
        arr[x][y] = i
        new_x, new_y = x + dx, y + dy
        if 0 <= new_x < n and 0 <= new_y < m and not arr[new_x][new_y]:
            x, y = new_x, new_y
        else:
            dx, dy = -dy, dx
            x, y = x + dx, y + dy


n = int(sys.argv[1])
m = int(sys.argv[2])
snail(n, m)