a-a a-b aaa aab aae aan aao aap aas ab- aba abb abe abn abo abp abs aea aeb aee aen aeo aep aes an- ana anb ane ann ano anp ans aoa aob aoe aon aoo aop aos ap- apa apb ape apn apo app aps as- asa asb ase asn aso asp ass b-p baa bab bae ban bao bap bas bba bbb bbe bbn bbo bbp bbs be- bea beb bee ben beo bep bes bna bnb bne bnn bno bnp bns boa bob boe bon boo bop bos bpa bpb bpe bpn bpo bpp bps bsa bsb bse bsn bso bsp bss eaa eab eae ean eao eap eas eba ebb ebe ebn ebo ebp ebs eea eeb eee een eeo eep ees en- ena enb ene enn eno enp ens eo- eoa eob eoe eon eoo eop eos ep- epa epb epe epn epo epp eps es- esa esb ese esn eso esp ess naa nab nae nan nao nap nas nba nbb nbe nbn nbo nbp nbs ne- nea neb nee nen neo nep nes nna nnb nne nnn nno nnp nns no- noa nob noe non noo nop nos npa npb npe npn npo npp nps nsa nsb nse nsn nso nsp nss oaa oab oae oan oao oap oas ob- oba obb obe obn obo obp obs oea oeb oee oen oeo oep oes on- ona onb one onn ono onp ons oo- ooa oob oon ooo oop oos op- opa opb ope opn opo opp ops os- osa osb ose osn oso osp oss p-p paa pab pae pan pao pap pas pba pbb pbe pbn pbo pbp pbs pea peb pee pen peo pep pes pn- pna pnb pne pnn pno pnp pns poa pob poe pon poo pop pos ppa ppb ppe ppn ppo ppp pps ps- psa psb pse psn pso psp pss saa sab sae san sao sap sas sba sbb sbe sbn sbo sbp sbs se- sea seb see sen seo sep ses sna snb sne snn sno snp sns soa sob soe son soo sop sos spa spb spe spn spo spp sps ss- ssa ssb sse ssn sso ssp sss