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