牛人帮我做一下python题，今晚十点交

def f(n,m):
    if m==0 or m==n:
        return 1
    return f(n-1,m-1) + f(n-1,m)
try:
    while True:
        a,b=map(int,input().split())
        print(f(a,b))    
except EOFError:
    pass