a-a a-b a-i aaa aab aai aam aao aas ab- aba abb abi abm abo abs ai- aia aib aii aim aio ais ama amb ami amm amo ams aoa aob aoi aom aoo aos as- asa asb asi asm aso ass baa bab bai bam bao bas bba bbb bbi bbm bbo bbs bi- bia bib bii bim bio bis bma bmb bmi bmm bmo bms boa bob boi bom boo bos bsa bsb bsi bsm bso bss ia- iaa iab iai iam iao ias iba ibb ibi ibm ibo ibs iia iib iii iim iio iis im- ima imb imi imm imo ims io- ioa iob ioi iom ioo ios is- isa isb isi ism iso iss m-o maa mab mai mam mao mas mba mbb mbi mbm mbo mbs mi- mia mib mii mim mio mis mma mmb mmi mmm mmo mms moa mob moi mom moo mos msa msb msi msm mso mss o-i oaa oab oai oam oao oas ob- oba obb obi obm obo obs oia oib oii oim oio ois om- oma omb omi omm omo oms oo- ooa oob ooi oom ooo oos os- osa osb osi osm oso oss saa sab sai sam sao sas sba sbb sbi sbm sbo sbs sia sib sii sim sio sis sma smb smi smm smo sms soa sob soi som soo sos ss- ssa ssb ssi ssm sso sss