a-a a-b a-c a-z aaa aab aac aan aar aay aaz ab- aba abb abc abn abr aby abz ac- aca acb acc acn acr acy acz an- ana anb anc ann anr any anz ar- ara arb arc arn arr ary arz ay- aya ayc ayn ayr ayz az- aza azb azn azy azz baa bab bac ban bar bay baz bba bbb bbc bbn bbr bby bca bcb bcc bcn bcr bcy bcz bna bnb bnc bnn bnr bnz bra brb brn brr bry brz by- bya byc byn byr byz bza bzn bzr bzz c-- caa cab cac can car cay caz cba cbb cbc cbn cbr cby cbz cca ccb ccc ccn ccr ccz cn- cna cnb cnc cnn cnr cny cra crb crc crn crr cry crz cya cyb cyc cyn cyr cz- czc naa nab nac nan nar nay naz nba nbb nbc nbn nbr nca ncb ncc ncn ncr nna nnb nnc nnn nnz nra nrb nrc nrn nrr nry nrz nya nyc nyn nyy nzb nzz ra- raa rab rac ran rar ray raz rba rbb rbc rbn rbr rca rcb rcc rcn rcr rna rnb rnc rnn rnr rny rnz rra rrb rrc rrn rrr ry- rya ryc ryn ryr ryy ryz rza rzb rzy yaa yab yac yan yar yay yaz ybc ybr yby ybz yca ycc ycy yna ynn yny yra yrc yrn yyb yyc yyy yyz yzb yzr yzy zaa zab zac zan zar zay zaz zbb zbc zbr zby znc znn zzr zzy zzz