#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define drep(i,n) for (int i = (n)-1; i >= 0; --i)
#define dup(x,y) (((x)+(y)-1)/(y))
#define ALL(x) (x).begin(), (x).end()
typedef long long ll;
typedef pair<int, int> pii;
const double EPS = 1e-10;
const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1000000007;
const double PI = acos(-1);
int dx[4] = {0,1,0,-1};
int dy[4] = {1,0,-1,0};
template<typename T> bool chmax(T &a, T b) {if(a<b){a=b; return 1; } return 0; }
template<typename T> bool chmin(T &a, T b) {if(a>b){a=b; return 1; } return 0; }
ll gcd(ll a, ll b) { return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}
ll mpow(ll x, ll p) {
	if (p==0) return 1;
	ll res=mpow(x,p/2); res=res*res%MOD;
	return p%2?res*x%MOD:res;
}
ll lpow(ll x, ll p) {
	if (p==0) return 1;
	ll res=lpow(x,p/2); res*=res;
	return p%2?res*x:res;
}

int main() {
	ll n;
	cin >> n;
	if (n == 0) {
		cout << 'X' << endl;
	} else {
		if ((n + 1) % 4) {
			cout << "O" << endl;
		} else {
			cout << "X" << endl;
		}
	}
}