-er a-a a-b aaa aab aae aah aao aap aar ab- aba abb abe abh abo abp abr aea aeb aee aeh aeo aep aer aha ahb ahe ahh aho ahp ahr aoa aob aoe aoh aoo aop aor ap- apa apb ape aph apo app apr ar- ara arb are arh aro arp arr b-p baa bab bae bah bao bap bar bba bbb bbe bbh bbo bbp bbr be- bea beb bee beh beo bep ber bha bhb bhe bhh bho bhp bhr boa bob boe boh boo bop bor bpa bpb bpe bph bpo bpp bpr bra brb bre brh bro brp brr eaa eab eae eah eao eap ear eba ebb ebe ebh ebo ebp ebr eea eeb eee eeo eep eer eha ehb ehe ehh eho ehp ehr eo- eoa eob eoe eoh eoo eop eor ep- epa epb epe eph epo epp epr era erb ere erh ero erp err haa hab hae hah hao hap har hba hbb hbe hbh hbo hbp hbr he- hea heb hee heh heo hep her hha hhb hhe hhh hho hhp hhr hoa hob hoe hoh hoo hop hor hpa hpb hpe hph hpo hpp hpr hr- hra hrb hre hrh hro hrp hrr oaa oab oae oah oao oap oar ob- oba obb obe obh obo obp obr oea oeb oee oeh oeo oep oer oha ohe ohh oho ohp ohr oo- ooa oob ooh ooo oop oor op- opa opb ope oph opo opp opr or- ora orb ore orh oro orp orr p-p paa pab pae pah pao pap par pba pbb pbe pbo pbp pbr pea peb pee peh peo pep per pha phb phe pho php phr poa pob poe poh poo pop por ppa ppb ppe pph ppo ppp ppr pra prb pre prh pro prp prr ra- raa rab rae rah rao rap rar rba rbb rbe rbh rbo rbp rbr re- rea reb ree reh reo rep rer rh- rha rhb rhe rhh rho rhp rhr roa rob roe roh roo rop ror rpa rpb rpe rph rpo rpp rpr rra rrb rrh rrp rrr