a-a a-b aaa aab aah aao aap aar ab- aba abb abh abo abp abr aha ahb ahh aho ahp ahr aoa aob aoh aoo aop aor ap- apa apb aph apo app apr ar- ara arb arh aro arp arr b-p baa bab bah bao bap bar bba bbb bbh bbo bbp bbr bha bhb bhh bho bhp bhr boa bob boh boo bop bor bpa bpb bph bpo bpp bpr bra brb brh bro brp brr haa hab hah hao hap har hba hbb hbh hbo hbp hbr hha hhb hhh hho hhp hhr hoa hob hoh hoo hop hor hpa hpb hph hpo hpp hpr hr- hra hrb hrh hro hrp hrr oaa oab oah oao oap oar ob- oba obb obh obo obp obr oha ohh oho ohp ohr oo- ooa oob ooh ooo oop oor op- opa opb oph opo opp opr or- ora orb orh oro orp orr p-p paa pab pah pao pap par pba pbb pbo pbp pbr pha phb pho php phr poa pob poh poo pop por ppa ppb pph ppo ppp ppr pra prb prh pro prp prr ra- raa rab rah rao rap rar rba rbb rbh rbo rbp rbr rh- rha rhb rhh rho rhp rhr roa rob roh roo rop ror rpa rpb rph rpo rpp rpr rra rrb rrh rrp rrr