// Code Written by : John Nixon
// Date: 09:11:2022  Time: 21:53:46
// Copyrights are applicable
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vi vector<int>
#define vll vector<long long int>
int main()
{
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    std::ios::sync_with_stdio(false);
    int t;
    cin >> t;
    while (t--)
    {
        int n;
        cin >> n;
        vector<int> a(n);

        for (int i = 0; i < n; i++)
        {
            cin >> a[i];
        }
        if (n <= 2)
        {
            cout << "YES" << endl;
        }
        else if (a[0] == a[n - 1])
        {
            cout << "YES" << endl;
        }
        else
        {
            bool flag = false;
            for (int i = 0; i < n - 1; i++)
            {
                if (a[i] == a[0] && a[i + 1] == a[n - 1])
                {
                    flag = true;
                    break;
                }
            }
            if (flag)
            {
                cout << "YES" << endl;
            }
            else
            {
                cout << "NO" << endl;
            }
        }
    }
    return;
}