D hf

D hfD hfD hfD hf
D hfD hfD hfD hfD hfD hfD hfD hf
D hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hf
D hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hfD hf
D hfD hfD hfD hfD hfD hfD hfD hf