a-a a-b a-c aaa aab aac aak aan aao aar aay ab- aba abb abc abk abn abo abr aby ac- aca acb acc ack acn aco acr acy aka akb akc akk akn ako akr an- ana anb anc ank ann ano anr any aoa aob aoc aok aon aoo aor ar- ara arb arc ark arn aro arr ary ay- aya ayc ayk ayn ayo ayr baa bab bac bak ban bao bar bay bba bbb bbc bbk bbn bbo bbr bby bca bcb bcc bck bcn bco bcr bcy bka bkb bkc bkk bkn bko bkr bna bnb bnc bnk bnn bno bnr boa bob boc bok bon boo bor boy bra brb brk brn bro brr bry by- bya byc byk byn byo byr c-- caa cab cac cak can cao car cay cba cbb cbc cbk cbn cbo cbr cby cca ccb ccc cck ccn cco ccr cka ckb ckc cko cky cn- cna cnb cnc cnn cno cnr cny co- coa cob coc cok con coo cor coy cra crb crc crk crn cro crr cry cya cyb cyc cyk cyn cyo cyr ka- kaa kab kac kak kan kao kar kay kba kbb kbc kbk kbn kbo kbr kca kcb kcc kck kcn kcr kkb kkc kkk kkn kkr kky kn- kna knc knk knn kno knr koa kob koc kok kon koo kor koy kra krc krk krn kro krr kry kya kyc kyn kyo kyr naa nab nac nak nan nao nar nay nba nbb nbc nbk nbn nbo nbr nca ncb ncc nck ncn nco ncr nka nkc nkk nkn nko nkr nky nna nnb nnc nnk nnn nno no- noa nob noc nok non noo nor noy nra nrb nrc nrk nrn nro nrr nry nya nyc nyk nyn nyo nyy oaa oab oac oak oan oao oar ob- oba obb obc obk obn obo obr oby oc- oca ocb occ ock ocn oco ocr oka okb okc okk oko okr on- ona onb onc onk onn ono onr ony oo- ooa oob ooc ook oon ooo oor or- ora orb orc ork orn oro orr ory oya oyo ra- raa rab rac rak ran rao rar ray rba rbb rbc rbk rbn rbo rbr rca rcb rcc rcn rco rcr rkb rkc rkk rko rky rna rnb rnc rnn rno rnr rny roa rob roc rok ron roo ror roy rra rrb rrc rrk rrn rrr ry- rya ryc ryk ryn ryo ryr ryy yaa yab yac yak yan yao yar yay ybc ybr yby yca ycc yco ycy yka ykk ykn yna ynk ynn yny yob yoc yok yon yoo yor yoy yra yrc yrn yro yyb yyc yyy