#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>



int main()
{
	int n = 0;
	scanf("%d", &n);
	int *p;
	p = (int *)malloc(sizeof(int)*n);
	for (int i = 0; i < n; i++)
		scanf("%d", &p[i]);
	int temp = 0;
	for (int i = 0; i < n - 1; i++)//排序
	{
		for (int j = 0; j < n - 1 - i; j++)
		{
			if (p[i] < p[i + 1])
			{
				temp = p[i + 1];
				p[i + 1] = p[i];
				p[i] = temp;
			}
		}
	}
	long long s = 0;
	int count = 0;
	for (int i = 0; i < n; i++)
	{
		s = s + p[i];
		count++;
		if (count == 3)//遇到3则减去
		{
			s = s - p[i];
			count = 0;
		}

	}
	printf("%lld", s);

	return 0;
}