题解 | #走方格的方案数#

n, m = list(map(int, input().strip().split()))
count = 0
def recursive(cur: tuple[int, int]):
    global count
    if cur[0] == n and cur[1] == m:
        count += 1
        return
    if cur[0] > n or cur[1] > m:
        return
    
    # 向右走
    recursive((cur[0]+1, cur[1]))
    # 向下走
    recursive((cur[0], cur[1] + 1))
    return count

recursive((0,0))
print(count)