a-a a-b a-t aaa aab aaf aam aao aar aas aat ab- aba abb abf abm abo abr abs abt af- afa afb aff afm afo afr afs aft ama amb amf amm amo amr ams amt aoa aob aof aom aoo aor aos aot ar- ara arb arf arm aro arr ars art as- asa asb asf asm aso asr ass ast at- ata atb atf atm ato atr ats att baa bab baf bam bao bar bas bat bba bbb bbf bbm bbo bbr bbs bbt bfa bfb bff bfm bfo bfr bfs bft bma bmb bmf bmm bmo bmr bms bmt boa bob bof bom boo bor bos bot bra brb brf brm bro brr brs brt bsa bsb bsf bsm bso bsr bss bst bta btb btf btm bto btr bts btt faa fab faf fam fao far fas fat fba fbb fbf fbm fbo fbr fbs fbt ffa fff ffm ffo ffr ffs fft fma fmb fmf fmm fmo fmr fms fmt foa fob fof fom foo for fos fot fra frb frf frm fro frr frs frt fsa fsb fsf fsm fso fsr fss fst fta ftb ftf ftm fto ftr fts ftt m-f m-o m-r maa mab maf mam mao mar mas mat mba mbb mbf mbm mbo mbr mbs mbt mfa mfb mff mfm mfo mfr mfs mft mma mmb mmf mmm mmo mmr mms mmt moa mob mof mom moo mor mos mot mra mrb mrf mrm mro mrr mrs mrt msa msb msf msm mso msr mss mst mta mtb mtf mtm mto mtr mts mtt oaa oab oaf oam oao oar oas oat ob- oba obb obf obm obo obr obs obt of- ofa ofb off ofm ofo ofr ofs oft om- oma omb omf omm omo omr oms omt oo- ooa oob oof oom ooo oor oos oot or- ora orb orf orm oro orr ors ort os- osa osb osf osm oso osr oss ost ot- ota otb otf otm oto otr ots ott ra- raa rab raf ram rao rar ras rat rba rbb rbf rbm rbo rbr rbs rbt rfa rfb rff rfm rfo rfr rfs rft rma rmb rmf rmm rmo rmr rms rmt roa rob rof rom roo ror ros rot rra rrb rrf rrm rrr rrs rrt rsa rsb rsf rsm rso rsr rss rst rta rtb rtf rtm rto rtr rts rtt saa sab saf sam sao sar sas sat sba sbb sbf sbm sbo sbr sbs sbt sfa sfb sff sfm sfo sfr sfs sft sma smb smf smm smo smr sms smt soa sob sof som soo sor sos sot sr- sra srb srf srm sro srr srs srt ss- ssa ssb ssf ssm sso ssr sss sst sta stb stf stm sto str sts stt taa tab taf tam tao tar tas tat tba tbb tbf tbm tbo tbr tbs tbt tfa tfb tff tfm tfo tfr tfs tft tma tmb tmf tmm tmo tmr tms tmt to- toa tob tof tom too tor tos tot tra trb trf trm tro trr trs trt tsa tsb tsf tsm tso tsr tss tst tta ttb ttf ttm tto ttr tts ttt