#include <iostream>
#include <cstdio>
#include <algorithm>
 
#define LL long long
using namespace std;
 
bool cmp(int a,int b){
return a>b;}
int main()
{
    int t,n,a[2333];
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        for(int i=1;i<=n;i++)scanf("%d",&a[i]);a[0]=0;
        sort(a,a+1+n,cmp);int ans=0;
        for(int i=0;i<n;i+=4)ans+=a[i]+a[i+1];
        printf("%d\n",ans);
    }
    return 0;
}