-er a-a a-b a-c aaa aab aac aae aam aao aap aar ab- aba abb abc abe abm abo abp abr ac- aca acb acc ace acm aco acp acr aea aeb aec aee aem aeo aep aer ama amb amc ame amm amo amp amr aoa aob aoc aoe aom aoo aop aor ap- apa apb apc ape apm apo app apr ar- ara arb arc are arm aro arp arr b-p baa bab bac bae bam bao bap bar bba bbb bbc bbe bbm bbo bbp bbr bca bcb bcc bce bcm bco bcp bcr be- bea beb bec bee bem beo bep ber bma bmb bmc bme bmm bmo bmp bmr boa bob boc boe bom boo bop bor bpa bpb bpc bpe bpm bpo bpp bpr bra brb bre brm bro brp brr c-- caa cab cac cae cam cao cap car cba cbb cbc cbe cbm cbo cbp cbr cca ccb ccc cce ccm cco ccp ccr ce- cea ceb cec cee cem ceo cep cer cma cmb cmc cme cmm cmo cmp cmr co- coa cob coc coe com coo cop cor cpa cpb cpc cpe cpm cpo cpp cpr cra crb crc cre crm cro crp crr eaa eab eac eae eam eao eap ear eba ebb ebc ebe ebm ebo ebp ebr ec- eca ecb ecc ece ecm eco ecr eea eeb eec eee eem eeo eep eer em- ema emb emc eme emm emo emp emr eo- eoa eob eoc eoe eom eoo eop eor ep- epa epb epc epe epm epo epp epr era erb erc ere erm ero erp err m-o m-r maa mab mac mae mam mao map mar mba mbb mbc mbe mbm mbo mbp mbr mc- mca mcb mcc mce mcm mco mcp mcr mea meb mec mee mem meo mep mer mma mmb mmc mme mmm mmo mmp mmr moa mob moc moe mom moo mop mor mpa mpb mpc mpe mpm mpo mpp mpr mra mrb mrc mre mrm mro mrp mrr oaa oab oac oae oam oao oap oar ob- oba obb obc obe obm obo obp obr oc- oca ocb occ ocm oco ocp ocr oea oeb oec oee oem oeo oep oer om- oma omb omc ome omm omo omp omr oo- ooa oob ooc oom ooo oop oor op- opa opb opc ope opm opo opp opr or- ora orb orc ore orm oro orp orr p-p paa pab pac pae pam pao pap par pba pbb pbc pbe pbm pbo pbp pbr pca pcb pcc pce pcm pco pcp pcr pea peb pec pee pem peo pep per pma pmb pmc pme pmm pmo pmp pmr poa pob poc poe pom poo pop por ppa ppb ppc ppe ppm ppo ppp ppr pra prb prc pre prm pro prp prr ra- raa rab rac rae ram rao rap rar rba rbb rbc rbe rbm rbo rbp rbr rca rcb rcc rce rcm rco rcp rcr re- rea reb rec ree rem reo rep rer rma rmb rmc rme rmm rmo rmp rmr roa rob roc roe rom roo rop ror rpa rpb rpc rpe rpm rpo rpp rpr rra rrb rrc rrm rrp rrr