#include <cstdio>
#include <cassert>
#include <algorithm>

const int MAXN = 100000;

int piles[MAXN];

void Work() {
  // Sort the array and output the sum of elements with a even index
  int n;
  assert(scanf("%d", &n) == 1);
  for (int i = 0; i < n; ++i)
    assert(scanf("%d", piles + i) == 1);
  std::sort(piles, piles + n, std::greater<int>());
  long long ans = 0;
  for (int i = 0; i < n; i += 2)
    ans += piles[i];
  printf("%lld\n", ans);
}

int main() {
  int cases;
  assert(scanf("%d", &cases) == 1);
  while (cases--) Work();
  return 0;
}