using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
static class Program{
	const int mod=(int)1e9+7;
	const double eps=1e-11;
	static void Main(){
		Sc sc=new Sc();
		var n=sc.I;
		var t=new string[]{"o-o","oo-","-oo","-o--","--o-","ooo"};
		Ac ac=new Ac(t,'-','x');
		StringBuilder sb=new StringBuilder();
		for(int i = 0;i<n;i++) {
			var s=sc.Sa;
			var ans='X';
			ac.Match(s[1],false,(a,e)=>{
				ans='O';
				return false;
			});
			if(ans=='X'){
				for(int j = 0,k=-1;j<s[1].Length;j++) {
					if(s[1][j]=='o'){
						if(k!=-1&&(k-j)%2==0){
							ans='O';
							break;
						}
						k=j;
					}
					else if(s[1][j]=='x'){k=-1;}
				}
			}
			sb.Append(ans+"\n");
		}
		Console.Write(sb);
	}
}
public class Ac{
	static private int o;
	public int n,cnt=1;
	public Nd root;
	public class Nd{
		public Nd[] ar;
		public List<Nd> li=new List<Nd>();
		public Nd sx;
		public List<string> stl=new List<string>();
		public int c,l=0,n;
		public bool b=false;
		public Nd(int c,int l){this.c=c-o;this.l=l;}
	}
	public Ac(string[] t,int a,int z){
		n=z-a+1;
		o=a;
		root=new Nd(a-1,0);
		for(int i = 0;i<t.Length;i++) {
			var r=root;
			for(int j = 0;j<t[i].Length;j++) {
				if(!r.b){r.ar=new Nd[n];r.b=true;}
				if(r.ar[t[i][j]-o]==null){r.li.Add(r=r.ar[t[i][j]-o]=new Nd(t[i][j],j+1));cnt++;}
				else{r=r.ar[t[i][j]-o];}
			}
			r.stl.Add(t[i]);
		}
		int p=1;
		var qu=new Queue<Nd>();
		for(int i = 0;i<root.li.Count;i++,p++) {
			root.li[i].sx=root;
			if(root.li[i].b){qu.Enqueue(root.li[i]);}
			root.li[i].n=p;
		}
		while(qu.Count>0){
			var e=qu.Dequeue();
			for(int i = 0;i<e.li.Count;i++,p++) {
				var r=e.sx;
				while(r!=null&&(!r.b||r.ar[e.li[i].c]==null)){r=r.sx;}
				e.li[i].sx=r!=null?r.ar[e.li[i].c]:root;
				if(e.li[i].sx.stl.Count>0){e.li[i].stl.AddRange(e.li[i].sx.stl);}
				if(e.li[i].b){qu.Enqueue(e.li[i]);}
				e.li[i].n=p;
			}
		}
	}
	public void Match(string t,bool bo,Action<int,Nd> f){
		var e=root;
		for(int i = 0;i<t.Length;i++) {
			while(e!=root&&(!e.b||e.ar[t[i]-o]==null)){e=e.sx;}
			if(e.ar[t[i]-o]!=null){e=e.ar[t[i]-o];}
			if(bo||e.stl.Count!=0){f(i,e);}
		}
	}
	public void Match(string t,bool bo,Func<int,Nd,bool> f){
		var e=root;
		for(int i = 0;i<t.Length;i++) {
			while(e!=root&&(!e.b||e.ar[t[i]-o]==null)){e=e.sx;}
			if(e.ar[t[i]-o]!=null){e=e.ar[t[i]-o];}
			if(bo||e.stl.Count!=0){
				if(!f(i,e)){break;}
			}
		}
	}
	public Nd Av(Nd e,char c){
		while(e!=root&&(!e.b||e.ar[c-o]==null)){e=e.sx;}
		if(e.ar[c-o]!=null){e=e.ar[c-o];}
		return e;
	}
}
public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),int.Parse);}
	public int[] Ia3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),long.Parse);}
	public long[] La3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}
	public double[] Da3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),double.Parse);}
	public double[] Da3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}