#include<iostream>
using namespace std;
int main(){
    int N;
    cin>>N;
    if(N<=0){
        cout<<"Invalid input";
        return 0;
    }
    for(int i=0;i<N;i++){
        for(int j=0;j<N;j++){
            if(i==j||i+j==N){
                cout<<"X ";
                else
                cout<"O ";
            }
        }
        cout<<endl;
    }
    return 0;
}