using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Globalization;
using System.Runtime.CompilerServices;

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)
        {
            var s = ReadLine().Split();
            ans[u] = Game(s[1]);
        }
        WriteLine(string.Join("\n", ans.Select(f => f ? "O" : "X")));
    }
    static bool Game(string s)
    {
        if (s.Contains("ooo") || s.Contains("oo-") || s.Contains("-oo") || s.Contains("o-o") || s.Contains("-o--") || s.Contains("--o-")) return true;
        var list = new List<(int id, char c)>();
        for (var i = 0; i < s.Length; ++i)
        {
            if (s[i] == 'o') list.Add((i, 'o'));
            else if (s[i] == 'x') list.Add((i, 'x'));
        }
        for (var i = 0; i + 1 < list.Count; ++i)
        {
            if (list[i].c == 'o' && list[i + 1].c == 'o' && (list[i + 1].id - list[i].id) % 2 == 0) return true;
        }
        return false;
    }
}