#include using namespace std; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define all(v) v.begin(),v.end() using ll=long long int; using pii=pair; using pdd=pair; const int mod=1000000000+7; const int inf=1000000; int main(){ int N; cin >> N; if(N%4==3)cout << "X" << endl; else cout << "O" << endl; return 0; }