#include<string>
#include<deque>
#include<queue>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<cmath>
#include<tuple>
using namespace std;
typedef long long int llint;
typedef int beet;
#define ween tuple
#define mp make_pair
#define mt make_tuple
#define pub push_back
#define puf push_front
#define pob pop_back
#define pof pop_front
#define izryt bool
#define fir first
#define sec second
#define res resize
#define ins insert
#define era erase
const llint mod=1000000007;
const llint big=1e9+1e8;
const llint red=0xE869120;
const llint pro=1002001;
//2n C n
int main(void){
	llint ans=1,n,i;
	cin>>n;
	if(n%4==3){cout<<"X"<<endl;}
	else {cout<<"O"<<endl;}
	return 0;
}