#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <set>
using namespace std;


int main() {
    int tests;
    cin >> tests;
    int* sums = new int[tests];
    for(int i = 0; i < tests; i++){
        int sum = 0;
        set<int, greater<int>> nums;
        int len;
        cin >> len;
        for(int j = 0; j < len; j++){
            int curr;
            cin >> curr;
            nums.insert(curr);
        }
        set<int> :: iterator itr;
        if(len % 2 == 0){
            for(itr = nums.begin(); itr != nums.end(); itr++){
                int a = *itr;
                itr++;
                int b = *itr;
                sum += a*b;
            }
        }else{
            for(itr = nums.begin(); itr != nums.end(); itr++){
                int a = *itr;
                itr++;
                if(itr == nums.end()){
                    break;
                }
                int b = *itr;
                sum += a*b;
            }
        }
        sums[i] = sum;
    }

    for(int i = 0; i < tests; i++){
        cout << sums[i] << " ";
    }
    return 0;
}