#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2 * 100 * 1000;
struct candy {
  int type, num, f;
  bool operator<(const candy &c) const {
    if (this->num != c.num) return this->num > c.num;
    if (this->f != c.f) return this->f < c.f;
    return this->type < c.type;
  }
  candy(int type, int num, int f) {
    this->type = type;
    this->num = num;
    this->f = f;
  }
};
int q, n, a[MAXN], b[MAXN];
set<int> ind;
void solveQuery();
int main() {
  ios::sync_with_stdio(false);
  cin >> q;
  for (int i = 0; i < q; i++) {
    while (ind.size()) {
      int tmp = *ind.begin();
      ind.erase(tmp);
      a[tmp] = b[tmp] = 0;
    }
    cin >> n;
    for (int j = 0; j < n; j++) {
      int t, f;
      cin >> t;
      a[t - 1]++;
      if (!f) b[t - 1]++;
      ind.insert(t - 1);
    }
    solveQuery();
  }
  return 0;
}
void solveQuery() {
  set<candy> s;
  for (set<int>::iterator it = ind.begin(); it != ind.end(); it++)
    s.insert(candy(*it, a[*it], b[*it]));
  int ans = 0, minF = 0, cnt = s.begin()->num;
  while (cnt && s.size()) {
    candy c = *s.begin();
    if (c.num > cnt) {
      s.erase(c);
      c.num--;
      if (c.f) c.f--;
      s.insert(c);
    } else {
      ans += c.num;
      minF += c.f;
      s.erase(c);
      cnt = c.num - 1;
      ;
    }
  }
  cout << ans << endl;
}
