#include <bits/stdc++.h>
using namespace std;
int main() {
  int _t;
  cin >> _t;
  for (int _ = 0; _ < (_t); ++_) {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < (n); ++i) cin >> a[i];
    sort(a.begin(), a.end());
    bool f = true;
    for (int i = 0; i < (n - 1); ++i) {
      if (abs(a[i] - a[i + 1]) <= 1) {
      } else
        f = false;
    }
    if (f)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
  return 0;
}
