#include <iostream>
using namespace std;
int main ()
{
    int h;
    cin>h;
    
    if(height<1||height>26){
        cout<<"invalid input";
    } 
    else
    {for(int i=0;i<h;i++)
    {
        char ch='A';
        
        for (int j=0;j<=i;j++)
        {
            cout<<ch<<"";
            ch++;
            
        }
        cout<<endl;
    }
    }
    return 0;
}