#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<int> a(n);
    for (auto &it : a) cin >> it;
    sort(a.begin(), a.end());
    bool ok = true;
    for (int i = 1; i < n; ++i) {
      ok &= (a[i] - a[i - 1] <= 1);
    }
    if (ok)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
  return 0;
}
