a-a a-b a-c aaa aab aac aah aao aar aay ab- aba abb abc abh abo abr aby ac- aca acb acc ach aco acr acy aha ahb ahc ahh aho ahr ahy aoa aob aoc aoh aoo aor ar- ara arb arc arh aro arr ary ay- aya ayc ayh ayo ayr baa bab bac bah bao bar bay bba bbb bbc bbh bbo bbr bby bca bcb bcc bch bco bcr bcy bha bhb bhc bhh bho bhr boa bob boc boh boo bor boy bra brb brh bro brr bry by- bya byc byh byo byr c-- caa cab cac cah cao car cay cba cbb cbc cbh cbo cbr cby cca ccb ccc cch cco ccr ch- cha chb chc chh cho chr chy co- coa cob coc coh coo cor coy cra crb crc crh cro crr cry cya cyb cyc cyo cyr haa hab hac hah hao har hay hba hbb hbc hbh hbo hbr hby hca hcb hcc hch hco hcr hcy hha hhb hhc hhh hho hhr hhy hoa hob hoc hoh hoo hor hoy hr- hra hrb hrc hrh hro hrr hy- hya hyb hyc hyh hyo hyr hyy oaa oab oac oah oao oar ob- oba obb obc obh obo obr oby oc- oca ocb occ och oco ocr oha ohc ohh oho ohr oo- ooa oob ooc ooh ooo oor or- ora orb orc orh oro orr ory oya oyo ra- raa rab rac rah rao rar ray rba rbb rbc rbh rbo rbr rca rcb rcc rch rco rcr rh- rha rhb rhc rhh rho rhr roa rob roc roh roo ror roy rra rrb rrc rrh rrr ry- rya ryc ryo ryr ryy yaa yab yac yah yao yar yay ybc ybr yby yca ycc ych yco ycy yha yhc yob yoc yoo yor yoy yra yrc yro yyb yyc yyy