a-a a-b a-c aaa aab aac aah aan aao aay ab- aba abb abc abh abn abo aby ac- aca acb acc ach acn aco acy aha ahb ahc ahh ahn aho ahy an- ana anb anc anh ann ano any aoa aob aoc aoh aon aoo ay- aya ayc ayh ayn ayo baa bab bac bah ban bao bay bba bbb bbc bbh bbn bbo bby bca bcb bcc bch bcn bco bcy bha bhb bhc bhh bho bna bnb bnc bnn bno boa bob boc boh bon boo boy by- bya byc byh byn byo c-- caa cab cac cah can cao cay cba cbb cbc cbh cbn cbo cby cca ccb ccc cch ccn cco ch- cha chb chc chh chn cho chy cn- cna cnb cnc cnh cnn cno cny co- coa cob coc coh con coo coy cya cyb cyc cyn cyo haa hab hac hah han hao hay hba hbb hbc hbh hbn hbo hby hca hcb hcc hch hcn hco hcy hha hhb hhc hhh hhn hho hhy hna hnb hnc hnh hnn hno hny hoa hob hoc hoh hon hoo hoy hy- hya hyb hyc hyh hyn hyo hyy naa nab nac nah nan nao nay nba nbb nbc nbn nbo nca ncb ncc nch ncn nco nha nhb nhc nhh nhn nhy nna nnb nnc nnh nnn nno no- noa nob noc noh non noo noy nya nyc nyn nyo nyy oaa oab oac oah oan oao ob- oba obb obc obh obn obo oby oc- oca ocb occ och ocn oco oha ohc ohh ohn oho on- ona onb onc onh onn ono ony oo- ooa oob ooc ooh oon ooo oya oyo yaa yab yac yah yan yao yay ybc yby yca ycc ych yco ycy yha yhc yna ynn yny yob yoc yon yoo yoy yyb yyc yyy