#include <bits/stdc++.h>
using namespace std;
void pairsort(long long a[], long long b[], long long n) {
  pair<long long, long long> pairt[n];
  for (long long i = 0; i < n; i++) {
    pairt[i].first = a[i];
    pairt[i].second = b[i];
  }
  sort(pairt, pairt + n);
  for (long long i = 0; i < n; i++) {
    a[i] = pairt[i].first;
    b[i] = pairt[i].second;
  }
}
bool isPrime(long long n) {
  for (long long i = 2; i <= sqrt(n); i++) {
    if (n % i == 0) return 0;
  }
  return 1;
}
long long tree[1400000];
long long a[1400000];
long long vis[1400000];
long long k = 0;
void buildtr(long long ss, long long se, long long ind) {
  if (ss == se) {
    tree[ind] = 0;
    return;
  }
  long long mid = (ss + se) / 2;
  buildtr(ss, mid, 2 * ind);
  buildtr(mid + 1, se, 2 * ind + 1);
  tree[ind] = 0;
}
void updatetr(long long ss, long long se, long long qs, long long qe,
              long long w, long long ind) {
  if (qe < ss || qs > se || vis[ind]) {
    return;
  }
  if (se <= qe && qs <= ss) {
    tree[ind] = w;
    vis[ind] = 1;
    return;
  }
  long long mid = (ss + se) / 2;
  updatetr(ss, mid, qs, qe, w, 2 * ind);
  updatetr(mid + 1, se, qs, qe, w, 2 * ind + 1);
}
void ansit(long long ss, long long se, long long ind, long long p) {
  if (!vis[ind])
    tree[ind] = p;
  else
    p = tree[ind];
  if (ss == se) {
    if (ss == tree[ind])
      cout << 0 << " ";
    else
      cout << tree[ind] + 1 << " ";
    return;
  }
  long long mid = (ss + se) / 2;
  ansit(ss, mid, 2 * ind, p);
  ansit(mid + 1, se, 2 * ind + 1, p);
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long q;
  cin >> q;
  while (q--) {
    long long n, sum = 0;
    cin >> n;
    long long a[n], vis[2000000] = {0};
    for (long long i = 0; i < n; i++) {
      cin >> a[i];
    }
    long long b[n], count = 1, cnt = 0;
    sort(a, a + n);
    for (long long i = 0; i < n - 1; i++) {
      if (a[i] == a[i + 1])
        count++;
      else {
        b[cnt++] = count;
        count = 1;
      }
    }
    b[cnt++] = count;
    sort(b, b + cnt);
    long long cur = b[cnt - 1];
    for (long long i = cnt - 1; i >= 0; i--) {
      if (b[i] < cur) cur = b[i];
      sum += cur;
      cur = cur - 1;
      if (cur == 0) break;
    }
    cout << sum << "\n";
  }
  return 0;
}
