-ey a-a a-b a-c aaa aab aac aae aak aas aay ab- aba abb abc abe abk abs aby ac- aca acb acc ace ack acs acy aea aeb aec aee aek aes aey aka akb akc ake akk aks as- asa asb asc ase ask ass asy ay- aya ayc aye ayk ays baa bab bac bae bak bas bay bba bbb bbc bbe bbk bbs bby bca bcb bcc bce bck bcs bcy be- bea beb bec bee bek bes bey bka bkb bkc bke bkk bks bsa bsb bsc bse bsk bss bsy by- bya byc bye byk bys c-- caa cab cac cae cak cas cay cba cbb cbc cbe cbk cbs cby cca ccb ccc cce cck ccs ce- cea ceb cec cee cek ces cey cka ckb ckc cks cky csa csb csc cse csk css csy cya cyb cyc cye cyk cys eaa eab eac eae eak eas eba ebb ebc ebe ebk ebs eby ec- eca ecb ecc ece eck ecs eea eeb eec eee eek ees eey eka ekb ekc eke eks eky es- esa esb esc ese esk ess esy eya eyc eye eys ka- kaa kab kac kae kak kas kay kba kbb kbc kbe kbk kbs kca kcb kcc kce kck kcs ke- kea keb kec kee kek kes key kkb kkc kke kkk kks kky ksa ksb ksc kse ksk kss kya kyc kye kys saa sab sac sae sak sas say sba sbb sbc sbe sbk sbs sby sca scb scc sce sck scs se- sea seb sec see sek ses sey sk- ska skb skc ske skk sks sky ss- ssa ssb ssc sse ssk sss sy- sya syb syc sye syk sys yaa yab yac yae yak yas yay ybc ybe ybs yby yca ycc yce ycs ycy yea yeb yec yee yek yes yey yka ykk ysa ysb ysc yse ysk yss ysy yyb yyc yye yys yyy