#include <bits/stdc++.h>
using namespace std;
double const PI = 3.141592653;
const int OO = 1000000000 + 9;
void fast() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL), cout.tie(NULL);
}
int main() {
  fast();
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<int> v(n);
    for (auto& i : v) {
      cin >> i;
    }
    v.push_back(0);
    sort(v.begin(), v.end());
    for (int i = 1; i <= n; i++) {
      if (i == n) {
        if (v[n - 1]) {
          if (v[n] - v[n - 1] <= 0) {
            v[n] = 0;
          }
        }
        continue;
      }
      if (v[i - 1] && v[i] - v[i - 1] <= 1) {
        v[i - 1] = 0;
        continue;
      }
      if (v[i + 1] && v[i + 1] - v[i] <= 1) {
        v[i] = 0;
        continue;
      }
    }
    int c = 0;
    for (auto i : v) {
      c += (i > 0);
    }
    cout << (c == 1 ? "YES" : "NO") << '\n';
  }
  return 0;
}
