// editor2
#include<iostream>
using namespace std;

    void triangle(int n)
    {
        if(n<1 || n>26)
        {
            cout<<"Invalid input";
            return ;
        }
        for(int i=1,i<=n,i++)
        {
            for(int j=0;j<i,j++)
            {
            cout<<char('A'+j)<<" ";
        }
        cout<<endl;
    }
    int main(){
        int height;
        cin>>height;
        triangle(height);
        return 0;
        
        
    }