-er a-a a-b a-i aaa aab aae aai aam aao aar ab- aba abb abe abi abm abo abr aea aeb aee aei aem aeo aer ai- aia aib aie aii aim aio air ama amb ame ami amm amo amr aoa aob aoe aoi aom aoo aor ar- ara arb are ari arm aro arr baa bab bae bai bam bao bar bba bbb bbe bbi bbm bbo bbr be- bea beb bee bei bem beo ber bi- bia bib bie bii bim bio bir bma bmb bme bmi bmm bmo bmr boa bob boe boi bom boo bor bra brb bre bri brm bro brr eaa eab eae eai eam eao ear eba ebb ebe ebi ebm ebo ebr eea eeb eee eem eeo eer eia eib eie eii eim eio eir em- ema emb eme emi emm emo emr eo- eoa eob eoe eoi eom eoo eor era erb ere eri erm ero err ia- iaa iab iae iai iam iao iar iba ibb ibe ibi ibm ibo ibr ie- iea iee iei iem ier iia iib iie iii iim iio iir im- ima imb ime imi imm imo io- ioa iob ioe ioi iom ioo ior ir- ira irb ire iri irm iro irr m-o m-r maa mab mae mai mam mao mar mba mbb mbe mbi mbm mbo mbr mea meb mee mei mem meo mer mi- mia mib mie mii mim mio mir mma mmb mme mmi mmm mmo mmr moa mob moe moi mom moo mor mra mrb mre mri mrm mro mrr o-i oaa oab oae oai oam oao oar ob- oba obb obe obi obm obo obr oea oeb oee oei oem oeo oer oia oib oie oii oim oio oir om- oma omb ome omi omm omo omr oo- ooa oob ooi oom ooo oor or- ora orb ore ori orm oro orr ra- raa rab rae rai ram rao rar rba rbb rbe rbi rbm rbo rbr re- rea reb ree rei rem reo rer ria rib rie rii rim rio rir rma rmb rme rmi rmm rmo rmr roa rob roe roi rom roo ror rra rrb rri rrm rrr