#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  int a[55];
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    memset(a, 0, sizeof(a));
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    sort(a, a + n);
    int flag = 1;
    if (a[0] == a[n - 1]) {
      cout << "YES" << endl;
      continue;
    }
    for (int i = 1; i < n; i++) {
      if ((a[i] - a[i - 1]) <= 1) {
        a[i - 1] = 0;
      } else {
        flag = 0;
        break;
      }
    }
    if (flag) {
      cout << "YES" << endl;
    } else
      cout << "NO" << endl;
  }
  return 0;
}
