//Nguyen Huu Hoang Minh
#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 2005
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "test"
#define int long long

using namespace std;

typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;
const int mod = 998244353;

int t;
int a[200005];

void readfile()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    if (fopen(Task".inp","r"))
    {
        freopen(Task".inp","r",stdin);
        //freopen(Task".out","w",stdout);
    }
    cin >> t;
}

void solve(){
    int n; cin >> n;
    for(int i=1; i<=n; i++) cin >> a[i];
    sort(a+1,a+1+n);
    if (n==1 && a[1]>1) cout << "NO \n";
    else if (n==1 && a[1]==1) cout << "YES \n";
    else{
        int ret = a[n] - a[n-1];
        if (ret <= 1) cout << "YES \n";
        else cout << "NO \n";
    }
}

void proc()
{
    while (t--){
        solve();
    }
}

signed main()
{
    readfile();
    proc();
    return 0;
}