a-a a-b aaa aab aae aan aao aau ab- aba abb abe abn abo abu aea aeb aee aen aeo aeu an- ana anb ane ann ano anu aoa aob aoe aon aoo aou au- aua aub aue aun auo b-u baa bab bae ban bao bau bba bbb bbe bbn bbo bbu be- bea beb bee ben beo beu bna bnb bne bnn bno bnu boa bob boe bon boo bou bua bub bue bun buo buu eaa eab eae ean eao eau eba ebb ebe ebn ebo ebu eea eeb eee een eeo en- ena enb ene enn eno enu eo- eoa eob eoe eon eoo eou eu- eua eub eue eun naa nab nae nan nao nau nba nbb nbe nbn nbo nbu ne- nea neb nee nen neo neu nna nnb nne nnn nno nnu no- noa nob noe non noo nou nua nub nue nun nuo nuu oaa oab oae oan oao oau ob- oba obb obe obn obo obu oea oeb oee oen oeo on- ona onb one onn ono onu oo- ooa oob oon ooo ou- oua oue oun ouo ua- uaa uab uae uan uao uau uba ubb ube ubn ubo ubu uea ueb uee uen un- una unb une unn uno unu uoa uob uoe uon uoo uua uue uun uuu