a-a a-c aaa aac aak aan aar aas ac- aca acc ack acn acr acs aka akc akk akn akr aks an- ana anc ank ann anr ans ar- ara arc ark arn arr ars as- asa asc ask asn asr ass c-- caa cac cak can car cas cca ccc cck ccn ccr ccs cka ckc cks cn- cna cnc cnn cnr cns cra crc crk crn crr crs csa csc csk csn csr css ka- kaa kac kak kan kar kas kca kcc kck kcn kcr kcs kkc kkk kkn kkr kks kn- kna knc knk knn knr kra krc krk krn krr krs ksa ksc ksk ksn ksr kss naa nac nak nan nar nas nca ncc nck ncn ncr ncs nka nkc nkk nkn nkr nks nna nnc nnk nnn nns nra nrc nrk nrn nrr nrs nsa nsc nsk nsn nsr nss ra- raa rac rak ran rar ras rca rcc rcn rcr rcs rkc rkk rks rna rnc rnn rnr rns rra rrc rrk rrn rrr rrs rsa rsc rsk rsn rsr rss saa sac sak san sar sas sca scc sck scn scr scs sk- ska skc skk skr sks sna snc snk snn snr sns sr- sra src srk srn srr srs ss- ssa ssc ssk ssn ssr sss