a-a a-b a-c aaa aab aac aae aah aao aap ab- aba abb abc abe abh abo abp ac- aca acb acc ace ach aco acp aea aeb aec aee aeh aeo aep aha ahb ahc ahe ahh aho ahp aoa aob aoc aoe aoh aoo aop ap- apa apb apc ape aph apo app b-p baa bab bac bae bah bao bap bba bbb bbc bbe bbh bbo bbp bca bcb bcc bce bch bco bcp be- bea beb bec bee beh beo bep bha bhb bhc bhe bhh bho bhp boa bob boc boe boh boo bop bpa bpb bpc bpe bph bpo bpp c-- caa cab cac cae cah cao cap cba cbb cbc cbe cbh cbo cbp cca ccb ccc cce cch cco ccp ce- cea ceb cec cee ceh ceo cep ch- cha chb chc che chh cho chp co- coa cob coc coe coh coo cop cpa cpb cpc cpe cph cpo cpp eaa eab eac eae eah eao eap eba ebb ebc ebe ebh ebo ebp ec- eca ecb ecc ece ech eco eea eeb eec eee eeo eep eha ehb ehc ehe ehh eho ehp eo- eoa eob eoc eoe eoh eoo eop ep- epa epb epc epe eph epo epp haa hab hac hae hah hao hap hba hbb hbc hbe hbh hbo hbp hca hcb hcc hce hch hco hcp he- hea heb hec hee heh heo hep hha hhb hhc hhe hhh hho hhp hoa hob hoc hoe hoh hoo hop hpa hpb hpc hpe hph hpo hpp oaa oab oac oae oah oao oap ob- oba obb obc obe obh obo obp oc- oca ocb occ och oco ocp oea oeb oec oee oeh oeo oep oha ohc ohe ohh oho ohp oo- ooa oob ooc ooh ooo oop op- opa opb opc ope oph opo opp p-p paa pab pac pae pah pao pap pba pbb pbc pbe pbo pbp pca pcb pcc pce pch pco pcp pea peb pec pee peh peo pep pha phb phc phe pho php poa pob poc poe poh poo pop ppa ppb ppc ppe pph ppo ppp