a-a a-b a-c aaa aab aac aah aak aan aar ab- aba abb abc abh abk abn abr ac- aca acb acc ach ack acn acr aha ahb ahc ahh ahk ahn ahr aka akb akc akh akk akn akr an- ana anb anc anh ank ann anr ar- ara arb arc arh ark arn arr baa bab bac bah bak ban bar bba bbb bbc bbh bbk bbn bbr bca bcb bcc bch bck bcn bcr bha bhb bhc bhh bhk bhr bka bkb bkc bkk bkn bkr bna bnb bnc bnk bnn bnr bra brb brh brk brn brr c-- caa cab cac cah cak can car cba cbb cbc cbh cbk cbn cbr cca ccb ccc cch cck ccn ccr ch- cha chb chc chh chk chn chr cka ckb ckc ckh cn- cna cnb cnc cnh cnn cnr cra crb crc crh crk crn crr haa hab hac hah hak han har hba hbb hbc hbh hbk hbn hbr hca hcb hcc hch hck hcn hcr hha hhb hhc hhh hhk hhn hhr hka hkb hkh hkk hkn hkr hna hnb hnc hnh hnk hnn hr- hra hrb hrc hrh hrk hrn hrr ka- kaa kab kac kah kak kan kar kba kbb kbc kbh kbk kbn kbr kca kcb kcc kch kck kcn kcr kha khh khk khn khr kkb kkc kkh kkk kkn kkr kn- kna knc knk knn knr kra krc krk krn krr naa nab nac nah nak nan nar nba nbb nbc nbk nbn nbr nca ncb ncc nch nck ncn ncr nha nhb nhc nhh nhk nhn nhr nka nkc nkk nkn nkr nna nnb nnc nnh nnk nnn nra nrb nrc nrk nrn nrr ra- raa rab rac rah rak ran rar rba rbb rbc rbh rbk rbn rbr rca rcb rcc rch rcn rcr rh- rha rhb rhc rhh rhn rhr rkb rkc rkk rna rnb rnc rnh rnn rnr rra rrb rrc rrh rrk rrn rrr