#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

ll N;

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);
    
    std::cin >> N;

    bool flag = ((N + 1) / 2) % 2 == 0;
    for(int i=1;i<32;++i){
        if(!(N >> i & 1) || (N % 2 == 1)){

        }else{
            flag = false;
            break;
        }
    }

    std::cout << "XO"[flag] << std::endl;
}