#include <bits/stdc++.h>
using namespace std;

#define int long long
#define rep(i, l, r) for (int i = (int)(l); i < (int)(r); i++)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)x.size())
template <class T> bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class T> using V = vector<T>;
using P = pair<int, int>;

/*
 */

signed main() {
  int n;
  cin >> n;

  int x = 0;
  rep(i, n/4*4, n+1){
    x ^= i;
  }

  /*
   * 100
   * 101
   * 110
   * 111
   * 000
   */

  cout << (x ? "O" : "X") << endl;

  return 0;
}