#include <bits/stdc++.h>
#define rep(i, n) rep2(i, 0, n)
#define rep2(i, j, n) for (ll i = (j); (i) < (n); ++(i))
#define pre(i,x) for(ll i=((ll)(x)-1);i>=0;i--)
#define all(x) (x).begin(),(x).end()
#define sz(x) (x).size()
#define pb push_back
#define fs first
#define sd second
#define vll vector<ll>
#define vvll vector<vector<ll>>
#define pll pair<ll, ll>
#define vpll vector<pair<ll, ll>>
#define mp make_pair
using namespace std;
using ll = long long;
using ull = unsigned long long;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
ll gcd(ll a, ll b) { if (a % b == 0) { return b; } else { return gcd(b, a % b); } }//最大公約数
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }//最小公倍数
bool comp(pll& f, pll& s) { return f.second < s.second; }//昇順に並び替える比較関数
const double PI = 3.141592653589793;
const int INF32 = 1 << 30, dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
const ll INF = 1ll << 60;
const ll MOD = 998244353;//1000000007;

int main() {
	ll N; cin >> N;
	ll flag = 1;
	if (N == 3)flag = 0;
	else if (N > 3) {
		if ((N - 3) % 4 == 0)flag = 0;
	}
	if (flag)cout << 'O' << endl;
	else cout << "X" << endl;
	return 0;
}