#include <bits/stdc++.h> 
using namespace std;
typedef long long ll;
ll INFL = 1000000000000000010;//10^18 = 2^60
int INF = 2000000000;//10^9
ll MOD  = 998244353;


int main() {
    ll N;
    cin >> N;
    if(N % 2 == 1){
        ll cnt = (N+1) / 2;
        if(cnt % 2 == 1){
            cout << "O" << endl;
        }else{
            cout << "X" << endl;
        }
    }
    else{
        ll cnt = N / 2;
        cnt %= 2;
        if(N xor cnt){
            cout << "O" << endl;
        }else{
            cout << "X" << endl;
        }
    }
    
}