a-a a-b a-c aaa aab aac aah aan aao aap ab- aba abb abc abh abn abo abp ac- aca acb acc ach acn aco acp aha ahb ahc ahh ahn aho ahp an- ana anb anc anh ann ano anp aoa aob aoc aoh aon aoo aop ap- apa apb apc aph apn apo app b-p baa bab bac bah ban bao bap bba bbb bbc bbh bbn bbo bbp bca bcb bcc bch bcn bco bcp bha bhb bhc bhh bho bhp bna bnb bnc bnn bno bnp boa bob boc boh bon boo bop bpa bpb bpc bph bpn bpo bpp c-- caa cab cac cah can cao cap cba cbb cbc cbh cbn cbo cbp cca ccb ccc cch ccn cco ccp ch- cha chb chc chh chn cho chp cn- cna cnb cnc cnh cnn cno cnp co- coa cob coc coh con coo cop cpa cpb cpc cph cpn cpo cpp haa hab hac hah han hao hap hba hbb hbc hbh hbn hbo hbp hca hcb hcc hch hcn hco hcp hha hhb hhc hhh hhn hho hhp hna hnb hnc hnh hnn hno hoa hob hoc hoh hon hoo hop hpa hpb hpc hph hpn hpo hpp naa nab nac nah nan nao nap nba nbb nbc nbn nbo nbp nca ncb ncc nch ncn nco ncp nha nhb nhc nhh nhn nhp nna nnb nnc nnh nnn nno nnp no- noa nob noc noh non noo nop npa npb npc nph npn npo npp oaa oab oac oah oan oao oap ob- oba obb obc obh obn obo obp oc- oca ocb occ och ocn oco ocp oha ohc ohh ohn oho ohp on- ona onb onc onh onn ono onp oo- ooa oob ooc ooh oon ooo oop op- opa opb opc oph opn opo opp p-p paa pab pac pah pan pao pap pba pbb pbc pbn pbo pbp pca pcb pcc pch pcn pco pcp pha phb phc phn pho php pn- pna pnb pnc pnh pnn pno pnp poa pob poc poh pon poo pop ppa ppb ppc pph ppn ppo ppp