#include <bits/stdc++.h>
using namespace std;
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
}
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<int> v(n);
    for (int i = 0; i < n; i++) cin >> v[i];
    sort(v.begin(), v.end());
    int flag = 0;
    for (int i = 0; i < n - 1; i++) {
      if (abs(v[i] - v[i + 1]) > 1) {
        cout << "NO" << endl;
        flag = 1;
        break;
      }
    }
    if (flag == 0) cout << "YES" << endl;
  }
  return 0;
}
