import java.util.*;
public class Solution {
public static void main(String[] args) {
//Your code goes here
Scanner Sc=new Scanner(System.in);
int n=Sc.nextInt();
int i=1;
while(i<=n)
{
int j=1;
char m='A';
while(j<=i)
{
System.out.print((char)(m+n-i));
m++;
j++;
}
System.out.println();
i++;
}
}
}