a-a a-b a-i aaa aab aae aai aak aan aao ab- aba abb abe abi abk abn abo aea aeb aee aei aek aen aeo ai- aia aib aie aii aik ain aio aka akb ake aki akk akn ako an- ana anb ane ani ank ann ano aoa aob aoe aoi aok aon aoo baa bab bae bai bak ban bao bba bbb bbe bbi bbk bbn bbo be- bea beb bee bei bek ben beo bi- bia bib bie bii bik bin bio bka bkb bke bkk bkn bko bna bnb bne bni bnk bnn bno boa bob boe boi bok bon boo eaa eab eae eai eak ean eao eba ebb ebe ebi ebk ebn ebo eea eeb eee eek een eeo eia eib eie eii eik ein eio eka ekb eke eki eko en- ena enb ene eni enk enn eno eo- eoa eob eoe eoi eok eon eoo ia- iaa iab iae iai ian iao iba ibb ibe ibi ibk ibn ibo ie- iea iee iei iek ien iia iib iie iii iin iio ika ikb ike iki ikk iko in- ina inb ine ini ink inn ino io- ioa iob ioe ioi ion ioo ka- kaa kab kae kai kak kan kao kba kbb kbe kbi kbk kbn kbo ke- kea keb kee kei kek ken keo kia kib kie kii kik kin kio kkb kke kki kkk kkn kn- kna kne kni knk knn kno koa kob koe koi kok kon koo n-i naa nab nae nai nak nan nao nba nbb nbe nbi nbk nbn nbo ne- nea neb nee nei nek nen neo nia nib nie nii nik nin nio nka nke nki nkk nkn nko nna nnb nne nni nnk nnn nno no- noa nob noe noi nok non noo o-i oaa oab oae oai oak oan oao ob- oba obb obe obi obk obn obo oea oeb oee oei oen oeo oia oib oie oii oik oin oio oka okb oke oki okk oko on- ona onb one oni onk onn ono oo- ooa oob ooi ook oon ooo