using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var t = NN;
        var ans = new bool[t];
        for (var u = 0; u < t; ++u)
        {
            var n = NN;
            var a = NList;
            var list = new List<int>();
            foreach (var ai in a) if (ai != 1) list.Add(ai);
            var flg = true;
            for (var i = 0; i + 1 < list.Count; ++i)
            {
                if (list[i] == list[i + 1])
                {
                    flg = false;
                    break;
                }
            }
            ans[u] = flg && list.Count > 0 && list[0] != list[^1];
        }
        WriteLine(string.Join("\n", ans.Select(f => f ? "Yes" : "No")));
    }
}