Python代码RE 80%，不知道原因！求大佬指点！！！

a=int(input())
b=int(input())
l=0
r=1
while r**a<=b:
    l=r
    r=r*2
while l+1<r:
    mid=(l+r)//2
    if mid**a<=b:
        l=mid
    else:
        r=mid
if l**a<=b:
    print(l)
else:
    print(r)