-er a-a a-b a-c aaa aab aac aae aah aao aap aar ab- aba abb abc abe abh abo abp abr ac- aca acb acc ace ach aco acp acr aea aeb aec aee aeh aeo aep aer aha ahb ahc ahe ahh aho ahp ahr aoa aob aoc aoe aoh aoo aop aor ap- apa apb apc ape aph apo app apr ar- ara arb arc are arh aro arp arr b-p baa bab bac bae bah bao bap bar bba bbb bbc bbe bbh bbo bbp bbr bca bcb bcc bce bch bco bcp bcr be- bea beb bec bee beh beo bep ber bha bhb bhc bhe bhh bho bhp bhr boa bob boc boe boh boo bop bor bpa bpb bpc bpe bph bpo bpp bpr bra brb bre brh bro brp brr c-- caa cab cac cae cah cao cap car cba cbb cbc cbe cbh cbo cbp cbr cca ccb ccc cce cch cco ccp ccr ce- cea ceb cec cee ceh ceo cep cer ch- cha chb chc che chh cho chp chr co- coa cob coc coe coh coo cop cor cpa cpb cpc cpe cph cpo cpp cpr cra crb crc cre crh cro crp crr eaa eab eac eae eah eao eap ear eba ebb ebc ebe ebh ebo ebp ebr ec- eca ecb ecc ece ech eco ecr eea eeb eec eee eeo eep eer eha ehb ehc ehe ehh eho ehp ehr eo- eoa eob eoc eoe eoh eoo eop eor ep- epa epb epc epe eph epo epp epr era erb erc ere erh ero erp err haa hab hac hae hah hao hap har hba hbb hbc hbe hbh hbo hbp hbr hca hcb hcc hce hch hco hcp hcr he- hea heb hec hee heh heo hep her hha hhb hhc hhe hhh hho hhp hhr hoa hob hoc hoe hoh hoo hop hor hpa hpb hpc hpe hph hpo hpp hpr hr- hra hrb hrc hre hrh hro hrp hrr oaa oab oac oae oah oao oap oar ob- oba obb obc obe obh obo obp obr oc- oca ocb occ och oco ocp ocr oea oeb oec oee oeh oeo oep oer oha ohc ohe ohh oho ohp ohr oo- ooa oob ooc ooh ooo oop oor op- opa opb opc ope oph opo opp opr or- ora orb orc ore orh oro orp orr p-p paa pab pac pae pah pao pap par pba pbb pbc pbe pbo pbp pbr pca pcb pcc pce pch pco pcp pcr pea peb pec pee peh peo pep per pha phb phc phe pho php phr poa pob poc poe poh poo pop por ppa ppb ppc ppe pph ppo ppp ppr pra prb prc pre prh pro prp prr ra- raa rab rac rae rah rao rap rar rba rbb rbc rbe rbh rbo rbp rbr rca rcb rcc rce rch rco rcp rcr re- rea reb rec ree reh reo rep rer rh- rha rhb rhc rhe rhh rho rhp rhr roa rob roc roe roh roo rop ror rpa rpb rpc rpe rph rpo rpp rpr rra rrb rrc rrh rrp rrr