a-a a-b a-i a-t aaa aab aaf aai aat aay ab- aba abb abf abi abt aby af- afa afb aff afi aft afy ai- aia aib aif aii ait aiy at- ata atb atf ati att ay- aya ayf ayi ayt baa bab baf bai bat bay bba bbb bbf bbi bbt bby bfa bfb bff bfi bft bfy bi- bia bib bif bii bit biy bta btb btf bti btt bty by- bya byf byi byt faa fab faf fai fat fay fba fbb fbf fbi fbt ffa fff ffi fft ffy fia fib fif fii fit fta ftb ftf fti ftt fty fy- fya fyb fyi i-f ia- iaa iab iaf iai iat iba ibb ibf ibi ibt iby ifa ifb iff ifi ift ify iia iib iif iii iit ita itb itf iti itt ity iya iyt iyy taa tab taf tai tat tay tba tbb tbf tbi tbt tfa tfb tff tfi tft tia tib tif tii tit tiy tta ttb ttf tti ttt tty tya tyf tyt yaa yab yaf yai yat yay ybf ybi yby yfa yff yft yif yii yit yta ytf ytt yyb yyf yyt yyy