a-a a-b aaa aab aae aak aan aao aap aax ab- aba abb abe abk abn abo abp abx aea aeb aee aek aen aeo aep aex aka akb ake akk akn ako akp an- ana anb ane ank ann ano anp anx aoa aob aoe aok aon aoo aop aox ap- apa apb ape apk apn apo app apx ax- axa axe axk axn axo axp axx b-p baa bab bae bak ban bao bap bax bba bbb bbe bbk bbn bbo bbp bbx be- bea beb bee bek ben beo bep bex bka bkb bke bkk bkn bko bkp bkx bna bnb bne bnk bnn bno bnp bnx boa bob boe bok bon boo bop box bpa bpb bpe bpn bpo bpp bpx bxb bxn bxo bxx eaa eab eae eak ean eao eap eax eba ebb ebe ebk ebn ebo ebp ebx eea eeb eee eek een eeo eep eex eka ekb eke eko ekp en- ena enb ene enk enn eno enp eo- eoa eob eoe eok eon eoo eop ep- epa epb epe epn epo epp epx ex- exa exe exo exp exx ka- kaa kab kae kak kan kao kap kax kba kbb kbe kbk kbn kbo kbp kbx ke- kea keb kee kek ken keo kep kex kkb kke kkk kkn kkp kn- kna kne knk knn kno knp knx koa kob koe kok kon koo kop kpa kpe kpk kpn kpo kpp kxo naa nab nae nak nan nao nap nax nba nbb nbe nbk nbn nbo nbp nbx ne- nea neb nee nek nen neo nep nex nka nke nkk nkn nko nkp nna nnb nne nnk nnn nno nnp no- noa nob noe nok non noo nop nox npa npb npe npn npo npp oaa oab oae oak oan oao oap oax ob- oba obb obe obk obn obo obp obx oea oeb oee oen oeo oep oex oka okb oke okk oko okp on- ona onb one onk onn ono onp onx oo- ooa oob ook oon ooo oop oox op- opa opb ope opk opn opo opp opx ox- oxa oxb oxn oxo oxx p-p paa pab pae pak pan pao pap pax pba pbb pbe pbk pbn pbo pbp pbx pea peb pee pek pen peo pep pex pka pkb pke pkn pko pkp pn- pna pnb pne pnk pnn pno pnp pnx poa pob poe pok pon poo pop pox ppa ppb ppe ppk ppn ppo ppp ppx pxe pxk xaa xak xan xap xbe xbx xee xen xep xex xkb xke xna xnk xno xoa xok xon xoo xop xox xpa xpb xpe xpn xpo xpp xxo xxp xxx