package main

import (
	"bufio"
	"fmt"
	"os"
)

func nextColor(top, left byte) byte {
	for c := byte('A'); c <= 'Z'; c++ {
		if c != top && c != left {
			return c
		}
	}
	return 'A'
}

func main() {
	in := bufio.NewReader(os.Stdin)
	var n, m int
	fmt.Fscan(in, &n, &m)

	ans := make([][]byte, n)
	for i := range ans {
		ans[i] = make([]byte, m)
	}

	r, c := 0, 0
	h, w := n, m
	var top, left byte

	for {
		col := nextColor(top, left)
		s := h
		if w < s {
			s = w
		}
		for i := 0; i < s; i++ {
			for j := 0; j < s; j++ {
				ans[r+i][c+j] = col
			}
		}
		if h == w {
			break
		}
		if h < w {
			c += s
			w -= s
			left = col
		} else {
			r += s
			h -= s
			top = col
		}
	}

	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()
	for i := 0; i < n; i++ {
		out.Write(ans[i])
		if i+1 < n {
			out.WriteByte('\n')
		}
	}
}