a-a a-b aaa aab aae aak aau ab- aba abb abe abk abu aea aeb aee aek aeu aka akb ake akk aku au- aua aub aue auk b-u baa bab bae bak bau bba bbb bbe bbk bbu be- bea beb bee bek beu bka bkb bke bkk bua bub bue buk buu eaa eab eae eak eau eba ebb ebe ebk ebu eea eeb eee eek eka ekb eke eku eu- eua eub eue ka- kaa kab kae kak kau kba kbb kbe kbk kbu ke- kea keb kee kek kkb kke kkk kku kub kue kuk kuu ua- uaa uab uae uak uau uba ubb ube ubk ubu uea ueb uee uka ukb uke ukk uku uua uue uuu