// editor2
#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-1)
            cout<<"X";
            else
            cout<<"C";
        
    }