字母图形

import java.util.Arrays;
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		
		printChar(m, n);
	}
	
	public static void  printChar(int m,int n){
	
		for(int i = 0 ; i < n ; i++){
			char c = 'A';
			for(int k = i ; k >=0; k--){
				System.out.print((char)(c+k));
			}
			for(int k = 1 ; k < m-i; k++){
				System.out.print((char)(c+k));
			}
			System.out.println();
		}
	}
}