-ey a-a a-b a-c aaa aab aac aae aas aay ab- aba abb abc abe abs aby ac- aca acb acc ace acs acy aea aeb aec aee aes aey as- asa asb asc ase ass asy ay- aya ayc aye ays baa bab bac bae bas bay bba bbb bbc bbe bbs bby bca bcb bcc bce bcs bcy be- bea beb bec bee bes bey bsa bsb bsc bse bss bsy by- bya byc bye bys c-- caa cab cac cae cas cay cba cbb cbc cbe cbs cby cca ccb ccc cce ccs ce- cea ceb cec cee ces cey csa csb csc cse css csy cya cyb cyc cye cys eaa eab eac eae eas eba ebb ebc ebe ebs eby ec- eca ecb ecc ece ecs eea eeb eec eee ees eey es- esa esb esc ese ess esy eya eyc eye eys saa sab sac sae sas say sba sbb sbc sbe sbs sby sca scb scc sce scs se- sea seb sec see ses sey ss- ssa ssb ssc sse sss sy- sya syb syc sye sys yaa yab yac yae yas yay ybc ybe ybs yby yca ycc yce ycs ycy yea yeb yec yee yes yey ysa ysb ysc yse yss ysy yyb yyc yye yys yyy