#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 = 0; i < n; i++) cin >> A[i];
    sort(A.begin(), A.end());
    A.push_back(200);
    int idx = 0;
    int x = 0;
    for (int i = 0; i < n; i++) {
      if (abs(A[i] - A[i + 1]) > 1) x++;
    }
    if (x == 1)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
}
