题解 | 走方格的方案数

n,m = map(int,input().split())
n += 1
m += 1
dp = [[0]*(m+1) for _ in range(n+1)]
for i in range(1,n+1):
    dp[i][1] = 1
for j in range(1,m+1):
    dp[1][j] = 1
for i in range(2,n+1):
    for j in range(2,m+1):
        dp[i][j] = dp[i-1][j]+dp[i][j-1]
print(dp[n][m])