题解 | 二维斐波那契数列

n,m = map(int,input().split())
def fbnq(n,m):
    a = [[0] * (m+1) for _ in range(n+1)]
    for i in range(1,n+1):
        a[i][1] = 1
    for i in range(1,m+1):
        a[1][i] = 1
    if n>=2 and m>=2:
        for i in range(2,n+1):
            for j in range(2,m+1):
                a[i][j] = a[i-1][j]+a[i][j-1]
    return a


a = fbnq(n,m)
print(a[n][m]%(10**9+7))