#include <bits/stdc++.h>
#define FOR(i, a, n) for (int i = a; i < n; i++)
#define REP(w, n) FOR(w, 0, n)
using namespace std;
typedef long long ll;

int main()
{
	ll n;
	cin >> n;
	int a = 0;
	FOR(i, 1, n + 1)
	{
		a ^= i;
	}
	if (a > 0)
	{
		cout << "O" << endl;
	}
	else
		cout << "X" << endl;
	return (0);
}