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 scn = new Scanner(System.in);
        int N = scn.nextInt();
for (int i = 1 ; i <= N ; i++){
char ch = 'A';
for(int j =1 ; j<= i; j++){
    System.out.print(ch);
    ch++;
}
System.out.println();
}
    }
}