a-a a-b aaa aab aaf aam aao aas aau ab- aba abb abf abm abo abs abu af- afa afb aff afm afo afs afu ama amb amf amm amo ams amu aoa aob aof aom aoo aos aou as- asa asb asf asm aso ass asu au- aua aub auf aum auo aus b-u baa bab baf bam bao bas bau bba bbb bbf bbm bbo bbs bbu bfa bfb bff bfm bfo bfs bfu bma bmb bmf bmm bmo bms bmu boa bob bof bom boo bos bou bsa bsb bsf bsm bso bss bsu bua bub buf bum buo bus buu faa fab faf fam fao fas fau fba fbb fbf fbm fbo fbs fbu ffa fff ffm ffo ffs ffu fma fmb fmf fmm fmo fms fmu foa fob fof fom foo fos fou fsa fsb fsf fsm fso fss fsu fua fub fuf fum fuo fus fuu m-f m-o maa mab maf mam mao mas mau mba mbb mbf mbm mbo mbs mbu mfa mfb mff mfm mfo mfs mfu mma mmb mmf mmm mmo mms mmu moa mob mof mom moo mos mou msa msb msf msm mso mss msu mua mub muf mum mus muu oaa oab oaf oam oao oas oau ob- oba obb obf obm obo obs obu of- ofa ofb off ofm ofo ofs ofu om- oma omb omf omm omo oms omu oo- ooa oob oof oom ooo oos os- osa osb osf osm oso oss osu ou- oua ouf oum ouo ous saa sab saf sam sao sas sau sba sbb sbf sbm sbo sbs sbu sfa sfb sff sfm sfo sfs sfu sma smb smf smm smo sms smu soa sob sof som soo sos sou ss- ssa ssb ssf ssm sso sss ssu sua sub suf sum suo sus suu ua- uaa uab uaf uam uao uas uau uba ubb ubf ubo ubs ubu ufa uff ufm ufo ufs ufu um- uma umb umf umm umo ums umu uoa uob uom uoo uos usa usb usf usm uso uss usu uua uum uus uuu