#include<string>
#include<deque>
#include<queue>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<cmath>
#include<tuple>
//#include<map>
//65 1000000000000000000 1000000000000000000
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;

int main(void){
	unsigned int n,gen=0;
	scanf("%ud",&n);
	for(int i=1;i<=n;i++){
		gen^=i;
	}
	if(gen){printf("O\n");}
	else{printf("X\n");}
	return 0;
}