#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  string result[t];
  for (int i = 0; i < t; i++) {
    int n;
    cin >> n;
    int r[n];
    for (int j = 0; j < n; j++) {
      cin >> r[j];
    }
    sort(r, r + n);
    for (int s = 0; s < n - 1; s++) {
      if (abs(r[s] - r[s + 1]) <= 1)
        continue;
      else {
        result[i] = "NO\n";
        break;
      }
    }
    if (result[i] != "NO\n") result[i] = "YES\n";
  }
  for (int i = 0; i < t; i++) cout << result[i];
  return 0;
}
