a-a a-b a-c aaa aab aac aah aan aar ab- aba abb abc abh abn abr ac- aca acb acc ach acn acr aha ahb ahc ahh ahn ahr an- ana anb anc anh ann anr ar- ara arb arc arh arn arr baa bab bac bah ban bar bba bbb bbc bbh bbn bbr bca bcb bcc bch bcn bcr bha bhb bhc bhh bhr bna bnb bnc bnn bnr bra brb brh brn brr c-- caa cab cac cah can car cba cbb cbc cbh cbn cbr cca ccb ccc cch ccn ccr ch- cha chb chc chh chn chr cn- cna cnb cnc cnh cnn cnr cra crb crc crh crn crr haa hab hac hah han har hba hbb hbc hbh hbn hbr hca hcb hcc hch hcn hcr hha hhb hhc hhh hhn hhr hna hnb hnc hnh hnn hr- hra hrb hrc hrh hrn hrr naa nab nac nah nan nar nba nbb nbc nbn nbr nca ncb ncc nch ncn ncr nha nhb nhc nhh nhn nhr nna nnb nnc nnh nnn nra nrb nrc nrn nrr ra- raa rab rac rah ran rar rba rbb rbc rbh rbn rbr rca rcb rcc rch rcn rcr rh- rha rhb rhc rhh rhn rhr rna rnb rnc rnh rnn rnr rra rrb rrc rrh rrn rrr