#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    int t,n,sum,data[20005];
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        for(int i=0;i<n;i++){
            scanf("%d",&data[i]);
        }
        sort(data,data+n);
        sum = 0;
        for(int i=n-3;i>-1;i-=3){
            sum += data[i];
        }
        printf("%d\n",sum);
    }
    return 0;
}