a-a a-c aaa aac aae aaf aak aan aao aap ac- aca acc ace acf ack acn aco acp aea aec aee aef aek aen aeo aep af- afa afc afe aff afk afn afo afp aka akc ake akk akn ako akp an- ana anc ane anf ank ann ano anp aoa aoc aoe aof aok aon aoo aop ap- apa apc ape apf apk apn apo app c-- caa cac cae caf cak can cao cap cca ccc cce ccf cck ccn cco ccp ce- cea cec cee cef cek cen ceo cep cfa cfc cfe cff cfk cfn cfo cfp cka ckc cko cn- cna cnc cne cnf cnn cno cnp co- coa coc coe cof cok con coo cop cpa cpc cpe cpf cpk cpn cpo cpp eaa eac eae eaf eak ean eao eap ec- eca ecc ece ecf eck ecn eco eea eec eee eef eek een eeo eep ef- efa efc efe eff efo efp eka ekc eke ekf eko ekp en- ena enc ene enf enk enn eno enp eo- eoa eoc eoe eof eok eon eoo eop ep- epa epc epe epf epn epo epp faa fac fae faf fak fan fao fap fca fcc fce fcf fck fcn fco fcp fea fec fee fef fek fen feo fep ffa ffc ffe fff ffk ffn ffo ffp fka fkc fkf fkk fkp fna fnc fne fnf fnk fnn fnp foa foc foe fof fok fon foo fop fpa fpc fpe fpk fpn fpo fpp ka- kaa kac kae kaf kak kan kao kap kca kcc kce kck kcn kcp ke- kea kec kee kef kek ken keo kep kfa kfc kff kfo kkc kke kkk kkn kkp kn- kna knc kne knf knk knn kno knp koa koc koe kof kok kon koo kop kpa kpc kpe kpf kpk kpn kpo kpp naa nac nae naf nak nan nao nap nca ncc nce ncf nck ncn nco ncp ne- nea nec nee nef nek nen neo nep nfa nfc nfe nff nfk nfn nfo nfp nka nkc nke nkf nkk nkn nko nkp nna nnc nne nnf nnk nnn nno nnp no- noa noc noe nof nok non noo nop npa npc npe npf npn npo npp oaa oac oae oaf oak oan oao oap oc- oca occ ocf ock ocn oco ocp oea oec oee oef oen oeo oep of- ofa ofc ofe off ofn ofo ofp oka okc oke okk oko okp on- ona onc one onf onk onn ono onp oo- ooa ooc oof ook oon ooo oop op- opa opc ope opf opk opn opo opp p-p paa pac pae paf pak pan pao pap pca pcc pce pcf pck pcn pco pcp pea pec pee pef pek pen peo pep pfa pfc pfe pff pfk pfn pfo pfp pka pkc pke pkf pkn pko pkp pn- pna pnc pne pnf pnk pnn pno pnp poa poc poe pof pok pon poo pop ppa ppc ppe ppf ppk ppn ppo ppp