#include <bits/stdc++.h>
using namespace std;
int isprime(long long x) {
  long long z = x;
  x = sqrt(x) + 0.5;
  for (long long o = 2; o <= x; o++) {
    if (z % o == 0) {
      return o;
    }
  }
  return 0;
}
bool isfo(long long x = 0) {
  double o, z;
  o = sqrt(5 * x * x - 4);
  z = sqrt(5 * x * x + 4);
  if (o == (int)o || z == (int)z) {
    return true;
  } else {
    return false;
  }
}
int main() {
  ios::sync_with_stdio(false);
  int t, a;
  bool b = true;
  cin >> t;
  while (t--) {
    cin >> a;
    int arr[a];
    for (int x = 0; x < a; x++) {
      cin >> arr[x];
    }
    sort(arr, arr + a);
    for (int x = 0; x < a - 1; x++) {
      if (abs(arr[x] - arr[x + 1]) != 0 && abs(arr[x] - arr[x + 1]) != 1) {
        b = false;
      }
    }
    if (b) {
      cout << "YES\n";
    } else {
      cout << "NO\n";
    }
    b = true;
  }
  return 0;
}
