a-a a-c aaa aac aae aak aan aas ac- aca acc ace ack acn acs aea aec aee aek aen aes aka akc ake akk akn aks an- ana anc ane ank ann ans as- asa asc ase ask asn ass c-- caa cac cae cak can cas cca ccc cce cck ccn ccs ce- cea cec cee cek cen ces cka ckc cks cn- cna cnc cne cnn cns csa csc cse csk csn css eaa eac eae eak ean eas ec- eca ecc ece eck ecn ecs eea eec eee eek een ees eka ekc eke eks en- ena enc ene enk enn ens es- esa esc ese esk esn ess ka- kaa kac kae kak kan kas kca kcc kce kck kcn kcs ke- kea kec kee kek ken kes kkc kke kkk kkn kks kn- kna knc kne knk knn ksa ksc kse ksk ksn kss naa nac nae nak nan nas nca ncc nce nck ncn ncs ne- nea nec nee nek nen nes nka nkc nke nkk nkn nks nna nnc nne nnk nnn nns nsa nsc nse nsk nsn nss saa sac sae sak san sas sca scc sce sck scn scs se- sea sec see sek sen ses sk- ska skc ske skk sks sna snc sne snk snn sns ss- ssa ssc sse ssk ssn sss