a-a a-b a-t aaa aab aaf aan aao aar aas aat ab- aba abb abf abn abo abr abs abt af- afa afb aff afn afo afr afs aft an- ana anb anf ann ano anr ans ant aoa aob aof aon aoo aor aos aot ar- ara arb arf arn aro arr ars art as- asa asb asf asn aso asr ass ast at- ata atb atf atn ato atr ats att baa bab baf ban bao bar bas bat bba bbb bbf bbn bbo bbr bbs bbt bfa bfb bff bfn bfo bfr bfs bft bna bnb bnf bnn bno bnr bns bnt boa bob bof bon boo bor bos bot bra brb brf brn bro brr brs brt bsa bsb bsf bsn bso bsr bss bst bta btb btf btn bto btr bts btt faa fab faf fan fao far fas fat fba fbb fbf fbn fbo fbr fbs fbt ffa fff ffn ffo ffr ffs fft fna fnb fnf fnn fnr fns fnt foa fob fof fon foo for fos fot fra frb frf frn fro frr frs frt fsa fsb fsf fsn fso fsr fss fst fta ftb ftf ftn fto ftr fts ftt naa nab naf nan nao nar nas nat nba nbb nbf nbn nbo nbr nbs nbt nfa nfb nff nfn nfo nfr nfs nft nna nnb nnf nnn nno nns nnt no- noa nob nof non noo nor nos not nra nrb nrf nrn nro nrr nrs nrt nsa nsb nsf nsn nso nsr nss nst nta ntb ntf ntn nto ntr nts ntt oaa oab oaf oan oao oar oas oat ob- oba obb obf obn obo obr obs obt of- ofa ofb off ofn ofo ofr ofs oft on- ona onb onf onn ono onr ons ont oo- ooa oob oof oon ooo oor oos oot or- ora orb orf orn oro orr ors ort os- osa osb osf osn oso osr oss ost ot- ota otb otf otn oto otr ots ott ra- raa rab raf ran rao rar ras rat rba rbb rbf rbn rbo rbr rbs rbt rfa rfb rff rfn rfo rfr rfs rft rna rnb rnn rno rnr rns rnt roa rob rof ron roo ror ros rot rra rrb rrf rrn rrr rrs rrt rsa rsb rsf rsn rso rsr rss rst rta rtb rtf rtn rto rtr rts rtt saa sab saf san sao sar sas sat sba sbb sbf sbn sbo sbr sbs sbt sfa sfb sff sfn sfo sfr sfs sft sna snb snf snn sno snr sns snt soa sob sof son soo sor sos sot sr- sra srb srf srn sro srr srs srt ss- ssa ssb ssf ssn sso ssr sss sst sta stb stf stn sto str sts stt taa tab taf tan tao tar tas tat tba tbb tbf tbn tbo tbr tbs tbt tfa tfb tff tfn tfo tfr tfs tft tna tnb tnf tnn tno tnr tns tnt to- toa tob tof ton too tor tos tot tra trb trf trn tro trr trs trt tsa tsb tsf tsn tso tsr tss tst tta ttb ttf ttn tto ttr tts ttt