text: /* Praveen Kumar */
  
  #include<bits/stdc++.h>
  // #include<ext/pb_ds/assoc_container.hpp>
  // #include<ext/pb_ds/tree_policy.hpp>
  
  using namespace std;
  using namespace chrono;
  // using namespace __gnu_pbds;
  
  #define fastio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
  #define MOD 1000000007
  #define MOD1 998244353
  #define INF 1e18
  #define nline "\n"
  #define pb push_back
  #define ppb pop_back
  #define mp make_pair
  #define ff first
  #define ss second
  #define PI 3.141592653589793238462
  #define set_bits __builtin_popcountll
  #define sz(x) ((int)(x).size())
  #define all(x) (x).begin(), (x).end()
  
  #ifdef og_saint
  #define debug(x) cerr << #x<<" "; _print(x); cerr << endl;
  #else
  #define debug(x);
  #endif
  
  typedef long long ll;
  typedef unsigned long long ull;
  typedef long double lld;
  // typedef tree<pair<int, int>, null_type, less<pair<int, int>>, rb_tree_tag, tree_order_statistics_node_update > pbds; // find_by_order, order_of_key
  
  void _print(ll t) {cerr << t;}
  void _print(int t) {cerr << t;}
  void _print(string t) {cerr << t;}
  void _print(char t) {cerr << t;}
  void _print(lld t) {cerr << t;}
  void _print(double t) {cerr << t;}
  void _print(ull t) {cerr << t;}
  
  template <class T, class V> void _print(pair <T, V> p);
  template <class T> void _print(vector <T> v);
  template <class T> void _print(set <T> v);
  template <class T, class V> void _print(map <T, V> v);
  template <class T> void _print(multiset <T> v);
  template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.ff); cerr << ","; _print(p.ss); cerr << "}";}
  template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
  template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
  template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
  template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
  // void _print(pbds v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
  
  /*---------------------------------------------------------------------------------------------------------------------------*/
  ll gcd(ll a, ll b) {if (b > a) {return gcd(b, a);} if (b == 0) {return a;} return gcd(b, a % b);}
  ll expo(ll a, ll b, ll mod) {ll res = 1; while (b > 0) {if (b & 1)res = (res * a) % mod; a = (a * a) % mod; b = b >> 1;} return res;}
  void extendgcd(ll a, ll b, ll*v) {if (b == 0) {v[0] = 1; v[1] = 0; v[2] = a; return ;} extendgcd(b, a % b, v); ll x = v[1]; v[1] = v[0] - v[1] * (a / b); v[0] = x; return;} //pass an arry of size1 3
  ll mminv(ll a, ll b) {ll arr[3]; extendgcd(a, b, arr); return arr[0];} //for non prime b
  ll mminvprime(ll a, ll b) {return expo(a, b - 2, b);}
  bool revsort(ll a, ll b) {return a > b;}
  void swap(int &x, int &y) {int temp = x; x = y; y = temp;}
  ll combination(ll n, ll r, ll m, ll *fact, ll *ifact) {ll val1 = fact[n]; ll val2 = ifact[n - r]; ll val3 = ifact[r]; return (((val1 * val2) % m) * val3) % m;}
  void google(int t) {cout << "Case #" << t << ": ";}
  vector<ll> sieve(int n) {int*arr = new int[n + 1](); vector<ll> vect; for (int i = 2; i <= n; i++)if (arr[i] == 0) {vect.push_back(i); for (int j = 2 * i; j <= n; j += i)arr[j] = 1;} return vect;}
  ll mod_add(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a + b) % m) + m) % m;}
  ll mod_mul(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a * b) % m) + m) % m;}
  ll mod_sub(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a - b) % m) + m) % m;}
  ll mod_div(ll a, ll b, ll m) {a = a % m; b = b % m; return (mod_mul(a, mminvprime(b, m), m) + m) % m;}  //only for prime m
  ll phin(ll n) {ll number = n; if (n % 2 == 0) {number /= 2; while (n % 2 == 0) n /= 2;} for (ll i = 3; i <= sqrt(n); i += 2) {if (n % i == 0) {while (n % i == 0)n /= i; number = (number / i * (i - 1));}} if (n > 1)number = (number / n * (n - 1)) ; return number;} //O(sqrt(N))
  /*--------------------------------------------------------------------------------------------------------------------------*/
  void solve(){
      int t;
      cin >> t;
      while(t--){
          int n;
          cin >> n;
          vector<int> v(n);
          for(auto &val : v) cin >> val;
  
          sort(v.begin(), v.end());
          if(v[n-1]-v[n-2] > 1){
              cout << "NO" << endl;
          }else{
              cout << "YES" << endl;
          }
      }
  }
  int main() {
  #ifdef og_saint
  	freopen("Error.txt", "w", stderr);
  #endif
  	fastio();
  	auto start1 = high_resolution_clock::now();
  	solve();
  	auto stop1 = high_resolution_clock::now();
  	auto duration = duration_cast<microseconds>(stop1 - start1);
  #ifdef og_saint
  	cerr << "Time: " << duration . count() / 1000 << endl;
  #endif
  }