题解 | #求int型正整数在内存中存储时1的个数#

import sys
import math


def to_statistics(num):
    total = 0
    # 转化成二进制
    b_str = bin(num)
    # 去除开头的0b
    b_str = b_str[2:]
    # 把剩下的数字相加
    for c in b_str:
        total += int(c)
    return total
    

if __name__ == '__main__':
    num = int(sys.stdin.readline().strip())
    total = to_statistics(num)
    print(total)