a-a a-b a-c aaa aab aac aah aao aap ab- aba abb abc abh abo abp ac- aca acb acc ach aco acp aha ahb ahc ahh aho ahp aoa aob aoc aoh aoo aop ap- apa apb apc aph apo app b-p baa bab bac bah bao bap bba bbb bbc bbh bbo bbp bca bcb bcc bch bco bcp bha bhb bhc bhh bho bhp boa bob boc boh boo bop bpa bpb bpc bph bpo bpp c-- caa cab cac cah cao cap cba cbb cbc cbh cbo cbp cca ccb ccc cch cco ccp ch- cha chb chc chh cho chp co- coa cob coc coh coo cop cpa cpb cpc cph cpo cpp haa hab hac hah hao hap hba hbb hbc hbh hbo hbp hca hcb hcc hch hco hcp hha hhb hhc hhh hho hhp hoa hob hoc hoh hoo hop hpa hpb hpc hph hpo hpp oaa oab oac oah oao oap ob- oba obb obc obh obo obp oc- oca ocb occ och oco ocp oha ohc ohh oho ohp oo- ooa oob ooc ooh ooo oop op- opa opb opc oph opo opp p-p paa pab pac pah pao pap pba pbb pbc pbo pbp pca pcb pcc pch pco pcp pha phb phc pho php poa pob poc poh poo pop ppa ppb ppc pph ppo ppp