#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<utility>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<math.h>
using namespace std;
#define mod (1000000000+7)
#define N (10007)
#define INF 1e16
typedef long long ll;
typedef pair<ll,ll> P;



int main(void){
    ll n;
    cin>>n;
    ll ans = 0;
    if(n%2==0){
        ll num = n-2;
        ans =1^n;
        num/=2;
        if(num%2==0)num=0;
        else num=1;
        ans^=num;
    }
    else{
        ll num = n-1;
        ans = 1;
        num/=2;
        if(num%2==0)num=0;
        else num=1;
        ans^=num;
    }
    if(ans == 0)cout<<"X"<<endl;
    else cout<<"O"<<endl;
    return 0;
}