a-a a-b aaa aab aak aau aav ab- aba abb abk abu abv aka akb akk aku akv au- aua aub auk auv av- ava avb avk avu b-u baa bab bak bau bav bba bbb bbk bbu bka bkb bkk bkv bua bub buk buu bva bvb bvk bvu bvv ka- kaa kab kak kau kav kba kbb kbk kbu kkb kkk kku kkv kub kuk kuu kva kvb kvk kvv ua- uaa uab uak uau uav uba ubb ubk ubu ubv uka ukb ukk uku uua uuu uva uvb uvu uvv v-a vaa vab vak vau vav vba vbk vbv vka vkb vuk vuv vva vvb vvv