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