#include <bits/stdc++.h>
using namespace std;

typedef long long ll;


int main()
{
    int q;
    ios::sync_with_stdio(0);
    cin.tie(nullptr);
    cin >> q;
    for (int i = 0; i < q; ++i) {
        int n;
        cin >> n;
        vector <int> cnt(n + 1, 0);
        int x;
        for (int i = 0; i < n; ++i) {
            cin >> x;
            ++cnt[x];
        }
        vector <int> unused;
        for (int i = 0; i <= n; ++i) {
            if (cnt[i] != 0) {
                unused.push_back(cnt[i]);
            }
        }
        sort(unused.rbegin(), unused.rend());
        ll ans = 0;
        int arrp = 0, digp = n;
        while (digp != 0 && arrp != unused.size()) {
            if (digp <= unused[arrp]) {
                ans += digp;
                --digp;
                ++arrp;
            }
            else {
                --digp;
            }
        }
        cout << ans << "\n";
    }
    return 0;
}