#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<int> data;
    for (int i = 0; i < n; i++) {
      int p;
      cin >> p;
      data.push_back(p);
    }
    sort(data.begin(), data.end());
    set<int> ans;
    for (int i = 0; i < n - 1; i++) {
      ans.insert(abs(data[i] - data[i + 1]));
    }
    bool let = false;
    set<int>::iterator it = ans.begin();
    while (it != ans.end()) {
      if (*it > 1) {
        cout << "NO\n";
        let = true;
        break;
      }
      it++;
    }
    if (!let) {
      cout << "YES\n";
    }
  }
}
