Python代码，只有90分，一个RE

import sys
sys.set_int_max_str_digits(500000)
n,m=input().split()
n=int(n)
m=int(m)
if n==1 and m==1:
    print("0")
elif m==0:
    print("1")
else:
    f=[1,0,0,0,0,0,0,0,0,0,0,0,0,]
    for i in range(1,m+1):
        t=1
        for j in range(1,n+1):
            t*=f[i-1]
        f[i]+=+t+1
    print(f[m]-f[m-1])