import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 *
 * @author sebastian
 */
public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader leer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder build = new StringBuilder();
        int C = Integer.parseInt(leer.readLine());
        for (int i = 0; i < C; i++) {
            int lo=Integer.parseInt(leer.readLine());

            String precio = leer.readLine();
            String[] pre = precio.split(" ");
            int camb;

            int cont=0;
            int[] merca=new int[lo];
            for(int j=0;j< lo;j++){
            merca[j]=Integer.parseInt(pre[j]);

            }
            for (int c = 0; c < (lo - 1); c++) {
                for (int d = 0; d <lo - c - 1; d++) {
                    if (merca[d] < merca[d + 1]) {
                        camb = merca[d];
                        merca[d] = merca[d + 1];
                        merca[d + 1] = camb;
                    }
                }
            }
            if( lo>3){
            for(int Z=2;Z<=lo;Z=Z+3){

                cont=cont+merca[Z];

            }

            System.out.println(cont);
            }
        }
    }

}