a-a a-b aaa aab aae aak aan aau aax ab- aba abb abe abk abn abu abx aea aeb aee aek aen aeu aex aka akb ake akk akn aku an- ana anb ane ank ann anu anx au- aua aub aue auk aun aux ax- axa axe axk axn axx b-u baa bab bae bak ban bau bax bba bbb bbe bbk bbn bbu bbx be- bea beb bee bek ben beu bex bka bkb bke bkk bkn bkx bna bnb bne bnk bnn bnu bnx bua bub bue buk bun buu bux bxb bxn bxx eaa eab eae eak ean eau eax eba ebb ebe ebk ebn ebu ebx eea eeb eee eek een eex eka ekb eke eku en- ena enb ene enk enn enu eu- eua eub eue eun eux ex- exa exe exu exx ka- kaa kab kae kak kan kau kax kba kbb kbe kbk kbn kbu kbx ke- kea keb kee kek ken kex kkb kke kkk kkn kku kn- kna kne knk knn knu knx kub kue kuk kun kuu naa nab nae nak nan nau nax nba nbb nbe nbk nbn nbu nbx ne- nea neb nee nek nen neu nex nka nke nkk nkn nku nna nnb nne nnk nnn nnu nua nub nue nuk nun nuu nux ua- uaa uab uae uak uan uau uba ubb ube ubk ubn ubu ubx uea ueb uee uen uka ukb uke ukk ukn uku un- una unb une unk unn unu unx uua uue uun uuu uxb uxu xaa xak xan xau xbe xbx xee xen xeu xex xkb xke xna xnk xnu xue xun xxx