算法训练 二进制数数

def tostr(n):
    if n<2:
        return str(n)
    else:
        return str(tostr(n//2))+str(n%2)
L,R = map(int,input().split())
su =0
def sumer(str):
    sumnum = 0
    for i in range(len(str)):
        if str[i]=="1":
            sumnum+=1
    return sumnum
for ss in range(L,R+1):
    s = tostr(ss)
    su+=sumer(s)
print(su)