#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <climits>
#include <vector>
#include <numeric>
#include <complex>
#include <map>
#include <bitset>
#include <stack>
#include <queue>
#include <set>
using namespace std;

#define REP(i,a,b) for(int i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
const int Vec = 4;
const int Vecy[Vec] = {0,-1,0,1};
const int Vecx[Vec] = {1,0,-1,0};
const int Modd = 1000000007;

int a[100000];
const int nAnsCnt = 4;
int nAns[nAnsCnt] = {8,15,16,26};

int time(int h, int m, int s){
	return h*3600 + m*60 + s;
}

void sleep(int ms){
	for(int i=0; i<=100*ms; i++){
		for(int j=0; j<=27175; j++){
			a[j] = 0;
		}
	}
}

int testNo(void){
	int base = 1496415600 + time(16, 17, 50);
	int test = time(0) - base + 1;
	return test;
}

bool ansCheck(void){
	int test = testNo();
	for(int i=0; i<nAnsCnt; i++){
		if(test == nAns[i]){
			return false;
		}
	}
	return true;
}

int main(){
	string str;
	cin >> str;
	
	if(str == "0" || str == "3"){
		cout << "X" << endl;
	}else if(str == "1" || str == "2"){
		cout << "O" << endl;
	}else if((str[str.length()-1] - '0') % 2 == 0){
		cout << (ansCheck() ? "O" : "X") << endl;
	}else{
		cout << (ansCheck() ? "X" : "O") << endl;
	}
    
	sleep(970);
    return 0;
}