#include <bits/stdc++.h>
using namespace std;
#define rep(i, l, r) for (int i = (int)(l); i < (int)(r); i++)
#define rrep(i, r, l) for (int i = (int)(r); i > (int)(l); i--)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()

void solve() {
    long long n;
    cin >> n;
    if (n % 4 == 1 || n % 4 == 2) {
        cout << 'O' << '\n';
        return;
    }
    
    long long power = 2;
    rep(i, 0, 32) {
        long long m = n % (power << 1);
        m -= power;
        if (m % 2 == 0) {
            cout << 'O' << '\n';
            return;
        }
        power <<= 1;
    }

    cout << 'X' << '\n';
}

int main() {
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
}