a-a a-b aaa aab aad aak aao aap aar ab- aba abb abd abk abo abp abr ad- ada adb add adk ado adp adr aka akb akd akk ako akp akr aoa aob aod aok aoo aop aor ap- apa apb apd apk apo app apr ar- ara arb ard ark aro arp arr b-p baa bab bad bak bao bap bar bba bbb bbd bbk bbo bbp bbr bda bdb bdd bdk bdo bdp bdr bka bkb bkk bko bkp bkr boa bob bod bok boo bop bor bpa bpb bpd bpo bpp bpr bra brb brd brk bro brp brr daa dab dad dak dao dap dar dba dbb dbd dbk dbo dbp dbr dda ddb ddd ddk ddo ddp ddr dka dkb dkk dko dkp dkr doa dob dod dok doo dop dor dpa dpb dpd dpk dpo dpp dpr dra drb drd drk dro drp drr ka- kaa kab kad kak kao kap kar kba kbb kbd kbk kbo kbp kbr kda kdb kdk kdo kdp kdr kkb kkk kkp kkr koa kob kod kok koo kop kor kpa kpd kpk kpo kpp kpr kra krd krk kro krp krr oaa oab oad oak oao oap oar ob- oba obb obd obk obo obp obr oda odb odd odo odp odr oka okb okd okk oko okp okr oo- ooa oob ood ook ooo oop oor op- opa opb opd opk opo opp opr or- ora orb ord ork oro orp orr p-p paa pab pad pak pao pap par pba pbb pbd pbk pbo pbp pbr pda pdb pdd pdk pdo pdp pdr pka pkb pkd pko pkp pkr poa pob pod pok poo pop por ppa ppb ppd ppk ppo ppp ppr pra prb prd prk pro prp prr ra- raa rab rad rak rao rap rar rba rbb rbd rbk rbo rbp rbr rda rdb rdd rdo rdp rdr rkb rkk rko rkp roa rob rod rok roo rop ror rpa rpb rpd rpk rpo rpp rpr rra rrb rrd rrk rrp rrr