import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
class Main {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        for(int i=0;i<n;i++){
            char ch='A';
            for(int j=0;j<=i;j++){
                System.out.print(ch);
                ch=(char)(ch+1);
            }
            System.out.println();
        }
    }
}