a-a a-c aaa aac aae aaf aan aas ac- aca acc ace acf acn acs aea aec aee aef aen aes af- afa afc afe aff afn afs an- ana anc ane anf ann ans as- asa asc ase asf asn ass c-- caa cac cae caf can cas cca ccc cce ccf ccn ccs ce- cea cec cee cef cen ces cfa cfc cfe cff cfn cfs cn- cna cnc cne cnf cnn cns csa csc cse csf csn css eaa eac eae eaf ean eas ec- eca ecc ece ecf ecn ecs eea eec eee eef een ees ef- efa efc efe eff efs en- ena enc ene enf enn ens es- esa esc ese esf esn ess faa fac fae faf fan fas fca fcc fce fcf fcn fcs fea fec fee fef fen fes ffa ffc ffe fff ffn ffs fna fnc fne fnf fnn fns fsa fsc fse fsf fsn fss naa nac nae naf nan nas nca ncc nce ncf ncn ncs ne- nea nec nee nef nen nes nfa nfc nfe nff nfn nfs nna nnc nne nnf nnn nns nsa nsc nse nsf nsn nss saa sac sae saf san sas sca scc sce scf scn scs se- sea sec see sef sen ses sfa sfc sfe sff sfn sfs sna snc sne snf snn sns ss- ssa ssc sse ssf ssn sss