/*
 * Warmup Contest #2, September 4, 2010 Problem D 
 * Solution by Dennis Meng
 * Originally from http://ncpc.idi.ntnu.no/ncpc2007/ncpc2007problems.pdf (problem H) 
 * ACM NCPC 2007 Problem H
 * 
 * It is always best to purchase the three most expensive items together
 * (so the 3rd one is free). Repeat until there is nothing left. 
 *
 */

import java.util.Arrays;
import java.util.Scanner;

public class D 
{
	public static void main(String[] args) 
	{
		Scanner myScanner = new Scanner(System.in);
		int cases = myScanner.nextInt();
		for (int i = 0; i < cases; i++)
		{
			int arr[] = new int[myScanner.nextInt()];
			for (int j = 0; j < arr.length; j++)
			{
				arr[j] = myScanner.nextInt();
			}
			Arrays.sort(arr);
			int discount = 0;
			for (int k = arr.length - 3; k >= 0; k -= 3)
			{
				discount += arr[k];
			}
			System.out.println(discount);
		}
	}
}