题解 | #走方格的方案数#

n, m = map(int, input().split(" "))

dp = [[0 for _ in range(n+1)] for _ in range(m+1)]
dp[0][0] = 1

for i in range(m+1):
    dp[i][0] = 1

for j in range(n+1):
    dp[0][j] = 1

for i in range(1, m+1, 1):
    for j in range(1, n+1, 1):
        dp[i][j] = dp[i-1][j] + dp[i][j-1]

print(dp[m][n])