题解 | #走方格的方案数#递归YYDS

def methods(n, m):

    if n == 0 or m == 0:
        return 1
    if n == 1 and m == 1:
        return 2
    if (n == 2 and m == 1) or (n == 1 and m == 2):
        return 3
    else:
        return methods(n-1, m) + methods(n, m-1)


while  True:

    try:
        n, m = map(int, input().split())
        result = methods(n, m)
        print(result)
    except:
        break