#include <bits/stdc++.h>
using namespace std;
int main() {
  int test;
  cin >> test;
  while (test--) {
    int n;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    sort(a, a + n);
    int flag = 1;
    for (int i = 1; i < n; i++) {
      if (abs(a[i] - a[i - 1]) > 1) {
        flag = 0;
        break;
      }
    }
    if (flag)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
  return 0;
}
