#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
//using mint = static_modint<998244353>;
using mint = static_modint<1000000007>;
//using misht = static_modint<2147483647>;
using vm = vector<mint>;
using vvm = vector<vm>;
using pl = pair<ll,ll>;
#define rep(i,n) for(ll i=0;i<(ll)(n);++i)
#define reps(i,s,n) for(ll i=(s);i<(ll)(n);++i)
#define rep1(i,n) for(ll i=1;i<=(ll)(n);++i)
#define ts(i) to_string(i)
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
ostream &operator<<(ostream &o,const mint &m){cout<<m.val();return o;}
const long long INF = 1e18;

#ifdef DEBUG
#include <debug.hpp>
#endif

int main(){
#ifdef DEBUG
	cout << "--- Input ---" << endl;
#endif
	ll N;
	cin >> N;

#ifdef DEBUG
	cout << "--- Logic ---" << endl;
#endif

#ifdef DEBUG
	cout << "--- Answer ---" << endl;
#endif
	if(N%4==3)cout << "X" << endl;
	else cout << "O" << endl;

}
//cout << fixed << setprecision(9);