关键点是1.在内存中一个整型存储的是二进制的补码，

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>


int main()
{
  int a = 0;
  scanf("%d", &a);
  int i = 0; int count = 0;
  for (i = 0; i < 32; i++)
  {
    if ((a >> i & 1) == 1)
    count++;
    
  }
  printf("%d\n", count);
  return 0;
}