-er a-a a-b a-c aaa aab aac aae aak aam aao aap aar ab- aba abb abc abe abk abm abo abp abr ac- aca acb acc ace ack acm aco acp acr aea aeb aec aee aek aem aeo aep aer aka akb akc ake akk akm ako akp akr ama amb amc ame amk amm amo amp amr aoa aob aoc aoe aok aom aoo aop aor ap- apa apb apc ape apk apm apo app apr ar- ara arb arc are ark arm aro arp arr b-p baa bab bac bae bak bam bao bap bar bba bbb bbc bbe bbk bbm bbo bbp bbr bca bcb bcc bce bck bcm bco bcp bcr be- bea beb bec bee bek bem beo bep ber bka bkb bkc bke bkk bkm bko bkp bkr bma bmb bmc bme bmk bmm bmo bmp bmr boa bob boc boe bok bom boo bop bor bpa bpb bpc bpe bpm bpo bpp bpr bra brb bre brk brm bro brp brr c-- caa cab cac cae cak cam cao cap car cba cbb cbc cbe cbk cbm cbo cbp cbr cca ccb ccc cce cck ccm cco ccp ccr ce- cea ceb cec cee cek cem ceo cep cer cka ckb ckc ckm cko cma cmb cmc cme cmk cmm cmo cmp cmr co- coa cob coc coe cok com coo cop cor cpa cpb cpc cpe cpk cpm cpo cpp cpr cra crb crc cre crk crm cro crp crr eaa eab eac eae eak eam eao eap ear eba ebb ebc ebe ebk ebm ebo ebp ebr ec- eca ecb ecc ece eck ecm eco ecr eea eeb eec eee eek eem eeo eep eer eka ekb ekc eke eko ekp ekr em- ema emb emc eme emk emm emo emp emr eo- eoa eob eoc eoe eok eom eoo eop eor ep- epa epb epc epe epm epo epp epr era erb erc ere erk erm ero erp err ka- kaa kab kac kae kak kam kao kap kar kba kbb kbc kbe kbk kbm kbo kbp kbr kca kcb kcc kce kck kcm kcp kcr ke- kea keb kec kee kek kem keo kep ker kkb kkc kke kkk kkm kkp kkr kma kmb kmc kme kmk kmm kmo kmp koa kob koc koe kok kom koo kop kor kpa kpc kpe kpk kpm kpo kpp kpr kra krc krk kro krp krr m-o m-r maa mab mac mae mak mam mao map mar mba mbb mbc mbe mbk mbm mbo mbp mbr mc- mca mcb mcc mce mck mcm mco mcp mcr mea meb mec mee mek mem meo mep mer mka mkb mkc mke mkk mkm mko mkp mkr mma mmb mmc mme mmk mmm mmo mmp mmr moa mob moc moe mok mom moo mop mor mpa mpb mpc mpe mpk mpm mpo mpp mpr mra mrb mrc mre mrk mrm mro mrp mrr oaa oab oac oae oak oam oao oap oar ob- oba obb obc obe obk obm obo obp obr oc- oca ocb occ ock ocm oco ocp ocr oea oeb oec oee oem oeo oep oer oka okb okc oke okk oko okp okr om- oma omb omc ome omm omo omp omr oo- ooa oob ooc ook oom ooo oop oor op- opa opb opc ope opk opm opo opp opr or- ora orb orc ore ork orm oro orp orr p-p paa pab pac pae pak pam pao pap par pba pbb pbc pbe pbk pbm pbo pbp pbr pca pcb pcc pce pck pcm pco pcp pcr pea peb pec pee pek pem peo pep per pka pkb pkc pke pkm pko pkp pkr pma pmb pmc pme pmk pmm pmo pmp pmr poa pob poc poe pok pom poo pop por ppa ppb ppc ppe ppk ppm ppo ppp ppr pra prb prc pre prk prm pro prp prr ra- raa rab rac rae rak ram rao rap rar rba rbb rbc rbe rbk rbm rbo rbp rbr rca rcb rcc rce rcm rco rcp rcr re- rea reb rec ree rek rem reo rep rer rkb rkc rke rkk rkm rko rkp rma rmb rmc rme rmm rmo rmp rmr roa rob roc roe rok rom roo rop ror rpa rpb rpc rpe rpk rpm rpo rpp rpr rra rrb rrc rrk rrm rrp rrr