B
DD
F F F
HHHH
F F F
DD
B

#include<stdio.h>
#include<conio.h>
main ()
{
                int i,j;
                for(i='B';i<='H';i=i+2)
                {
                                for(j='B';j<=i;j=j+2)
                                {
                                                printf("%c",i);
                                }
                                printf("\n");
                }


                for(i='F';i>='B';i=i-2)
                {
                                for(j='B';j<=i;j=j+2)
                                {
                                                printf("%c",i);
                                }
                                printf("\n");
                }
}