ddd dde ddn ddp ddx de- ded dee den dep dex dnd dne dnn dnp dpd dpe dpn dpp dxd dxn dxp dxx ed- edd ede edn edp edx eed eee een eep eex en- end ene enn enp ep- epd epe epn epp epx ex- exd exe exp exx ndd nde ndn ndp ne- ned nee nen nep nex nne nnn nnp npd npe npn npp nxd p-p pdd pde pdn pdp pdx ped pee pen pep pex pn- pnd pne pnn pnp pnx ppd ppe ppn ppp ppx pxe xde xed xee xen xep xex xpd xpe xpn xpp xxp xxx