#include <bits/stdc++.h>
//#include <atcoder/all>

using namespace std;
//using namespace atcoder;

using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using ld = long double;
using vld = vector<ld>;
using vb = vector<bool>;

#define rep(i, n) for (ll i = 0; i < (n); i++)
#ifdef LOCAL
#define dbg(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl
#else
#define dbg(x) true
#endif

template <class T> bool chmin(T& a, T b) {
    if(a > b) { a = b; return true; }
    else return false;
}

template <class T> bool chmax(T& a, T b) {
    if(a < b) { a = b; return true; }
    else return false;
}

template <class T> ostream& operator<<(ostream& s, const vector<T>& a) {
    for(auto i : a) s << i << ' ';
    return s;
}

constexpr int INF = 1 << 30;
constexpr ll INFL = 1LL << 60;
constexpr ld EPS = 1e-12;
ld PI = acos(-1.0);

// https://yukicoder.me/problems/no/524
void solve() {
    ll n;
    cin >> n;
    char c;
    if(n % 4 == 3) c = 'X';
    else c = 'O';
    cout << c << endl;
    return;
}

int main() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    solve();
}