uva 11369 - Shopaholic

#include<bits/stdc++.h>

using namespace std;

/// Typedef
typedef long long ll;

#define sc1(a) scanf("%lld",&a)
#define sc2(a,b) scanf("%lld %lld",&a,&b)

#define pf1(a) printf("%lld\n",a)
#define pf2(a,b) printf("%lld %lld\n",a,b)

#define mx 10000007
#define mod 100000007
#define PI acos(-1.0)

int dr[] = {-2,-2,-1,-1,1,1,2,2};
int dc[] = {-1,1,-2,2,-2,2,-1,1};

int main()
{
    ll num, m, tc = 1;

   // freopen("/media/morol/574830c2-aaf8-40d8-9a94-7a029a2e831f/coding/clion/p1/output.txt", "w", stdout);

   sc1(tc);

   while (tc--){

       sc1(num);
       ll arr[num];

       for(ll i = 0; i < num; i++){
           sc1(arr[i]);
       }

       sort(arr, arr + num, greater<ll>());

       ll sum = 0;
       for(ll i = 2; i < num; i+=3){
           sum += arr[i];
       }

       pf1(sum);
   }

    return 0;

}