#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 5;
void solve() {
  int n;
  cin >> n;
  vector<int> v(n);
  map<int, int> mpp;
  for (int i = 0; i < n; i++) {
    cin >> v[i];
    mpp[v[i]]++;
  }
  int ans1 = 0, ans2 = 0;
  bool flag = false;
  for (int i = 0; i <= 100; i++) {
    if (mpp[i] >= 2) {
      if (!flag) {
        ans1++;
      }
      ans2++;
    } else if (mpp[i] == 1) {
      flag = true;
      ans2++;
    } else {
      break;
    }
  }
  cout << ans1 + ans2 << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long t = 1;
  cin >> t;
  while (t--) solve();
  cerr << "Time : " << 1000 * ((double)clock()) / (double)CLOCKS_PER_SEC
       << "ms\n";
  return 0;
}
