-ey a-a a-b a-c a-t aaa aab aac aae aas aat aay ab- aba abb abc abe abs abt aby ac- aca acb acc ace acs act acy aea aeb aec aee aes aet aey as- asa asb asc ase ass ast asy at- ata atb atc ate ats att ay- aya ayc aye ays ayt baa bab bac bae bas bat bay bba bbb bbc bbe bbs bbt bby bca bcb bcc bce bcs bct bcy be- bea beb bec bee bes bet bey bsa bsb bsc bse bss bst bsy bta btb btc bte bts btt bty by- bya byc bye bys byt c-- caa cab cac cae cas cat cay cba cbb cbc cbe cbs cbt cby cca ccb ccc cce ccs cct ce- cea ceb cec cee ces cet cey csa csb csc cse css cst csy cta ctb ctc cte cts ctt cty cya cyb cyc cye cys cyt eaa eab eac eae eas eat eba ebb ebc ebe ebs ebt eby ec- eca ecb ecc ece ecs ect eea eeb eec eee ees eet eey es- esa esb esc ese ess est esy eta etb etc ete ets ett ety eya eyc eye eys eyt saa sab sac sae sas sat say sba sbb sbc sbe sbs sbt sby sca scb scc sce scs sct se- sea seb sec see ses set sey ss- ssa ssb ssc sse sss sst sta stb stc ste sts stt sty sy- sya syb syc sye sys syt taa tab tac tae tas tat tay tba tbb tbc tbe tbs tbt tca tcb tcc tce tcs tct te- tea teb tec tee tes tet tey tsa tsb tsc tse tss tst tsy tta ttb ttc tte tts ttt tty tya tyc tye tys tyt yaa yab yac yae yas yat yay ybc ybe ybs yby yca ycc yce ycs ycy yea yeb yec yee yes yet yey ysa ysb ysc yse yss yst ysy yta ytc yte yts ytt yyb yyc yye yys yyt yyy