#include <iostream>
#include <algorithm>
#include <cstdio>
#include <string>

#define ll long long

using namespace std;

int main(){

 int n;
 cin>>n;
 int judge=0;
 for(int i=1;i<=n;++i) judge^=i;
 if(judge) cout<<"O"<<endl;
 else cout<<"X"<<endl;
 return 0;
}