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[] NMi => ReadLine().Split().Select(c => int.Parse(c) - 1).ToArray();
    static int[][] NMap(int n) => Enumerable.Repeat(0, n).Select(_ => NMi).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var t = NN;
        var ans = new bool[t];
        for (var u = 0; u < t; ++u)
        {
            ReadLine();
            var s = ReadLine();
            var ks = 0;
            var ps = 0;
            for (var i = 0; i < s.Length; ++i)
            {
                if (i == 0 || s[i - 1] != s[i])
                {
                    if (s[i] == 'K') ++ks;
                    else if (s[i] == 'P') ++ps;
                }
            }
            ans[u] = ks >= ps;
        }
        WriteLine(string.Join("\n", ans.Select(f => f ? "K" : "P")));
    }
}