a-a a-b aaa aab aae aak aan aao aap ab- aba abb abe abk abn abo abp aea aeb aee aek aen aeo aep aka akb ake akk akn ako akp an- ana anb ane ank ann ano anp aoa aob aoe aok aon aoo aop ap- apa apb ape apk apn apo app b-p baa bab bae bak ban bao bap bba bbb bbe bbk bbn bbo bbp be- bea beb bee bek ben beo bep bka bkb bke bkk bkn bko bkp bna bnb bne bnk bnn bno bnp boa bob boe bok bon boo bop bpa bpb bpe bpn bpo bpp eaa eab eae eak ean eao eap eba ebb ebe ebk ebn ebo ebp eea eeb eee eek een eeo eep 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 ka- kaa kab kae kak kan kao kap kba kbb kbe kbk kbn kbo kbp ke- kea keb kee kek ken keo kep kkb kke kkk kkn kkp kn- kna kne knk knn kno knp koa kob koe kok kon koo kop kpa kpe kpk kpn kpo kpp naa nab nae nak nan nao nap nba nbb nbe nbk nbn nbo nbp ne- nea neb nee nek nen neo nep nka nke nkk nkn nko nkp nna nnb nne nnk nnn nno nnp no- noa nob noe nok non noo nop npa npb npe npn npo npp oaa oab oae oak oan oao oap ob- oba obb obe obk obn obo obp oea oeb oee oen oeo oep oka okb oke okk oko okp on- ona onb one onk onn ono onp oo- ooa oob ook oon ooo oop op- opa opb ope opk opn opo opp p-p paa pab pae pak pan pao pap pba pbb pbe pbk pbn pbo pbp pea peb pee pek pen peo pep pka pkb pke pkn pko pkp pn- pna pnb pne pnk pnn pno pnp poa pob poe pok pon poo pop ppa ppb ppe ppk ppn ppo ppp