#include <bits/stdc++.h>
using namespace std;
const int N = 200;
const int mod = 1e9 + 7;
int a[N];
int main() {
  int _;
  scanf("%d", &_);
  while (_--) {
    int n, x, l = 0;
    scanf("%d", &n);
    memset(a, 0, sizeof(a));
    for (int i = 0; i < n; i++) {
      scanf("%d", &x);
      a[x] = 1;
    }
    bool ok = 1;
    for (int i = 1; i <= 100; i++) {
      if (a[i]) {
        if (l == 0) l = i;
        if (abs(i - l) > 1) {
          ok = 0;
          break;
        }
        l = i;
      }
    }
    if (ok)
      printf("YES\n");
    else
      printf("NO\n");
  }
}
