#include <bits/stdc++.h>
using namespace std;
int main() {
  int m;
  std::cin >> m;
  while (m > 0) {
    int n, x, y;
    std::cin >> n;
    priority_queue<int, vector<int>, std::less<int>> ans;
    for (int i = 0; i < n; i++) {
      std::cin >> x;
      ans.push(x);
    }
    while (ans.size() > 1) {
      y = ans.top();
      ans.pop();
      if (y - (ans.top()) <= 1) {
        continue;
      } else {
        std::cout << "NO" << endl;
        while (!ans.empty()) ans.pop();
        break;
      }
    }
    if (ans.size() == 1) {
      std::cout << "YES" << endl;
    }
    while (!ans.empty()) ans.pop();
    m--;
  }
}
