喝汽水问题

假设一瓶汽水1元，两个空瓶换一瓶汽水，有20元，能喝多少瓶汽水？

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
	int money = 0;
	int count = 0;
	int empty = 0;
	scanf("%d", &money);
	//买回来的汽水喝掉
	count = money;
	empty = money;
  //换回来的汽水
	while (empty>=2)
	{
		count += empty / 2;
		empty = empty / 2 + empty % 2;
	}
	printf("%d", count);
	return 0;
}