#include <cmath>
#include <vector>
#include <map>
#include <set>
#include <functional>
#include <queue>
#include <iostream>
#include <string.h>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <cstdint>
#include <climits>
#include <unordered_set>
#include <sstream>

using namespace std;

#define ll long long int
#define pii pair<int,int>

int main()
{
    ll n;
    cin >> n;
    string o = "O";
    string x = "X";
    if(n == 1)
    {
        cout << o << endl;
        return 0;
    }
    else
    {
        if(n % 2 == 0)
        {
            cout << o << endl;
            return 0;
        }
        else
        {
            cout << x << endl;
            return 0;
        }
    }
}