#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int& i : a) cin >> i;
    sort(a.begin(), a.end());
    int i;
    for (i = 1; i < n; i++) {
      if (abs(a[i] - a[i - 1]) <= 1)
        continue;
      else
        break;
    }
    if (i == n)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
}
