a-a a-b a-i aaa aab aaf aai aam aao aas ab- aba abb abf abi abm abo abs af- afa afb aff afi afm afo afs ai- aia aib aif aii aim aio ais ama amb amf ami amm amo ams aoa aob aof aoi aom aoo aos as- asa asb asf asi asm aso ass baa bab baf bai bam bao bas bba bbb bbf bbi bbm bbo bbs bfa bfb bff bfi bfm bfo bfs bi- bia bib bif bii bim bio bis bma bmb bmf bmi bmm bmo bms boa bob bof boi bom boo bos bsa bsb bsf bsi bsm bso bss faa fab faf fai fam fao fas fba fbb fbf fbi fbm fbo fbs ffa fff ffi ffm ffo ffs fia fib fif fii fim fis fma fmb fmf fmi fmm fmo fms foa fob fof foi fom foo fos fsa fsb fsf fsi fsm fso fss i-f ia- iaa iab iaf iai iam iao ias iba ibb ibf ibi ibm ibo ibs ifa ifb iff ifi ifm ifo ifs iia iib iif iii iim iio iis im- ima imb imf imi imm imo ims io- ioa iob iof ioi iom ioo ios is- isa isb isf isi ism iso iss m-f m-o maa mab maf mai mam mao mas mba mbb mbf mbi mbm mbo mbs mfa mfb mff mfi mfm mfo mfs mi- mia mib mif mii mim mio mis mma mmb mmf mmi mmm mmo mms moa mob mof moi mom moo mos msa msb msf msi msm mso mss o-i oaa oab oaf oai oam oao oas ob- oba obb obf obi obm obo obs of- ofa ofb off ofi ofm ofo ofs oia oib oif oii oim oio ois om- oma omb omf omi omm omo oms oo- ooa oob oof ooi oom ooo oos os- osa osb osf osi osm oso oss saa sab saf sai sam sao sas sba sbb sbf sbi sbm sbo sbs sfa sfb sff sfi sfm sfo sfs sia sib sif sii sim sio sis sma smb smf smi smm smo sms soa sob sof soi som soo sos ss- ssa ssb ssf ssi ssm sso sss