#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  for (int i = 0; i < t; ++i) {
    int n;
    cin >> n;
    int *arr = new int[n];
    for (int j = 0; j < n; ++j) {
      cin >> arr[j];
    }
    sort(arr, arr + n);
    for (int j = 0; j < n; ++j) {
      if (j == n - 1) {
        cout << "YES\n";
        break;
      }
      if (abs(arr[j] - arr[j + 1]) > 1) {
        cout << "NO\n";
        break;
      }
    }
  }
}
