a-a a-b a-i aaa aab aae aai aak aan aas ab- aba abb abe abi abk abn abs aea aeb aee aei aek aen aes ai- aia aib aie aii aik ain ais aka akb ake aki akk akn aks an- ana anb ane ani ank ann ans as- asa asb ase asi ask asn ass baa bab bae bai bak ban bas bba bbb bbe bbi bbk bbn bbs be- bea beb bee bei bek ben bes bi- bia bib bie bii bik bin bis bka bkb bke bkk bkn bks bna bnb bne bni bnk bnn bns bsa bsb bse bsi bsk bsn bss eaa eab eae eai eak ean eas eba ebb ebe ebi ebk ebn ebs eea eeb eee eek een ees eia eib eie eii eik ein eis eka ekb eke eki eks en- ena enb ene eni enk enn ens es- esa esb ese esi esk esn ess ia- iaa iab iae iai ian ias iba ibb ibe ibi ibk ibn ibs ie- iea iee iei iek ien ies iia iib iie iii iin iis ika ikb ike iki ikk iks in- ina inb ine ini ink inn ins is- isa isb ise isi isk isn iss ka- kaa kab kae kai kak kan kas kba kbb kbe kbi kbk kbn kbs ke- kea keb kee kei kek ken kes kia kib kie kii kik kin kis kkb kke kki kkk kkn kks kn- kna kne kni knk knn ksa ksb kse ksi ksk ksn kss n-i naa nab nae nai nak nan nas nba nbb nbe nbi nbk nbn nbs ne- nea neb nee nei nek nen nes nia nib nie nii nik nin nis nka nke nki nkk nkn nks nna nnb nne nni nnk nnn nns nsa nsb nse nsi nsk nsn nss saa sab sae sai sak san sas sba sbb sbe sbi sbk sbn sbs se- sea seb see sei sek sen ses sia sib sie sii sik sin sis sk- ska skb ske ski skk sks sna snb sne sni snk snn sns ss- ssa ssb sse ssi ssk ssn sss