#include <stdio.h>
#include<string.h>
#include<math.h>
#include<algorithm>
using namespace std;
bool cmp(int a,int b){return a>b;}
int x[20001];
int main(){
int t,i,n,sum;
scanf("%d",&t);
while(t--){
scanf("%d",&n);
for(i=1;i<=n;i++){
scanf("%d",&x[i]);
}
sort(x+1,x+n+1,cmp);
sum=0;
for(i=3;i<=n;i+=3)
sum+=x[i];
printf("%d\n",sum);
}
return 0;
}