a-a a-b a-c aaa aab aac aag aak aar aay ab- aba abb abc abg abk abr aby ac- aca acb acc acg ack acr acy ag- aga agb agc agg agk agr agy aka akb akc akg akk akr ar- ara arb arc arg ark arr ary ay- aya ayc ayk ayr baa bab bac bag bak bar bay bba bbb bbc bbg bbk bbr bby bca bcb bcc bcg bck bcr bcy bga bgb bgc bgg bgk bgr bka bkb bkc bkg bkk bkr bra brb brg brk brr bry by- bya byc byg byk byr c-- caa cab cac cag cak car cay cba cbb cbc cbg cbk cbr cby cca ccb ccc ccg cck ccr cga cgb cgc cgg cgr cgy cka ckb ckc cky cra crb crc crg crk crr cry cya cyb cyc cyg cyk cyr gaa gab gac gag gak gar gay gba gbc gbg gbk gbr gby gca gcb gcc gcg gck gcr gga ggb ggc ggg ggr gka gkb gra grb grc grg grk grr gry gy- gya gyb gyr ka- kaa kab kac kag kak kar kay kba kbb kbc kbk kbr kca kcb kcc kcg kck kcr kga kgb kgc kgy kkb kkc kkk kkr kky kra krc krg krk krr kry kya kyc kyr ra- raa rab rac rag rak rar ray rba rbb rbc rbg rbk rbr rca rcb rcc rcg rcr rga rgb rgc rgg rgk rgr rkb rkc rkg rkk rky rra rrb rrc rrg rrk rrr ry- rya ryc ryg ryk ryr ryy yaa yab yac yag yak yar yay ybc ybg ybr yby yca ycc ycy yga ygc yka ykk yra yrc yrg yyb yyc yyg yyy