a-a a-b a-i a-t aaa aab aaf aai aas aat aay ab- aba abb abf abi abs abt aby af- afa afb aff afi afs aft afy ai- aia aib aif aii ais ait aiy as- asa asb asf asi ass ast asy at- ata atb atf ati ats att ay- aya ayf ayi ays ayt baa bab baf bai bas bat bay bba bbb bbf bbi bbs bbt bby bfa bfb bff bfi bfs bft bfy bi- bia bib bif bii bis bit biy bsa bsb bsf bsi bss bst bsy bta btb btf bti bts btt bty by- bya byf byi bys byt faa fab faf fai fas fat fay fba fbb fbf fbi fbs fbt ffa fff ffi ffs fft ffy fia fib fif fii fis fit fsa fsb fsf fsi fss fst fta ftb ftf fti fts ftt fty fy- fya fyb fyi i-f ia- iaa iab iaf iai ias iat iba ibb ibf ibi ibs ibt iby ifa ifb iff ifi ifs ift ify iia iib iif iii iis iit is- isa isb isf isi iss ist isy ita itb itf iti its itt ity iya iys iyt iyy saa sab saf sai sas sat say sba sbb sbf sbi sbs sbt sby sfa sfb sff sfi sfs sft sia sib sif sii sis sit ss- ssa ssb ssf ssi sss sst sta stb stf sti sts stt sty sy- sya syb syi sys syt taa tab taf tai tas tat tay tba tbb tbf tbi tbs tbt tfa tfb tff tfi tfs tft tia tib tif tii tis tit tiy tsa tsb tsf tsi tss tst tsy tta ttb ttf tti tts ttt tty tya tyf tys tyt yaa yab yaf yai yas yat yay ybf ybi ybs yby yfa yff yfs yft yif yii yis yit ysa ysb ysi yss yst ysy yta ytf yts ytt yyb yyf yys yyt yyy