import sys

n = bin(int(input()))[2:] 
m ,tem = 0,0

for i in n:
    if i == '0':
        tem = max(tem,m)
        m = 0
    else:
        m += 1
tem = max(tem,m)
print(tem)     

1.二进制转换是字符串的形式返回,同时保留'0b',因此从索引2开始取数

2.最后还需要判断最后一段连续的'1'字符是不是最长的连续字符串