import java.util.Scanner;
public class W {
/*
A B C D E F G
B A B C D E F
C B A B C D E
D C B A B C D
E D C B A B C
*/
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int i = scanner.nextInt();
int j = scanner.nextInt();
char chars[][] = new char[i][j];
for (int x = 0; x < i; x++) {
char a = 'A';
char b = (char)(65+x);
for (int y = 0; y < j; y++) {
if (x>y) {
System.out.print(b--);
}
if (x<=y) {
System.out.print(a++);
}
}
System.out.println();
}
}
}
package shiti;
import java.util.Scanner;
/*
A B C D E F G
B A B C D E F
C B A B C D E
D C B A B C D
E D C B A B C
*/
public class W1 {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int x = scanner.nextInt();
int y = scanner.nextInt();
for (int i = 0; i < x; i++) {
for (int j = 0; j < y; j++) {
if (i>j) {
System.out.print((char)(65+i-j));
}
if (i<=j) {
System.out.print((char)(65-i+j));
}
}
System.out.println();
}
}
}