#if 1
#ifdef INCLUDED_MAIN
int main() {
    REDIRCT_IO;
    ll N;
    cin >> N;
    cout << ((N+1) % 4 == 0 ? "X" : "O") << endl;
    RESTORE_IO;
    return 0;
}

#else

#include<bits/stdc++.h>
#ifdef _INTEGRAL_MAX_BITS
#include"C:\Users\Spare\source\repos\Competitive_programming\Competitive_programming\debugging.h"
#endif
#ifndef DEBUGGING
#define MY_MAIN int main()
#define REDIRCT_IO ;
#define RESTORE_IO ;
#endif
#define sc static
#define ct const
#define ft first
#define sd second
using namespace std;
using ld = long double;
using ll = long long;
using cchar = const char;
using cint = const int;
using cll = const ll;
using uchar = unsigned char;
using uint = unsigned int;
using ull = unsigned long long;
using cuchar = const uchar;
using cuint = const uint;
using cull = const ull;
template<class TYPE> static const TYPE INF = numeric_limits<TYPE>::max();
#define rep(i, n) for(int i = (0), fend = n; i < fend; ++i)
static const string ascii_lowercase = "abcdefghijklmnopqrstuvwxyz";
static const string ascii_uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
#define INCLUDED_MAIN
#include __FILE__
#endif

#endif