#include <bits/stdc++.h>
#define int long long
#define sqrtl(x) sqrt(x)
using namespace std;

namespace solve {
  namespace test_case {
    void main() {
      int n; cin >> n;
      vector<int> a(n);
      for (auto &x: a) cin >> x;
      auto sum = accumulate(a.begin(), a.end(), 0LL);
      int l (0), r (1e9), mex (1);
      while (l <= r) {
        int m ((l + r) / 2);
        if (m * (m + 1) / 2 <= sum) l = m + 1, mex = m + 1;
        else r = m - 1;
      }
      cout << mex << '\n';
    }
  }

  void main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t (1); cin >> t; 
    while (t--) {
      test_case::main();
    }
  }
}

signed main() { solve::main(); }