a-ak a-be aaaa aaab aaad aaae aaba aabb aabd aada aade aaea aaka aake abaa abab abad abae abak abb- abba abbb abbe abda abed abee adaa adab adad adae adak adba adda addd adde adea adeb adee aede aeka akaa akae aked akee akka baaa baad baak baba babb babe bada badb badd bade baed baek bak- baka bake bbad bbbb bbdd bbeb bead beak beba bebb bebe beda bede beeb beed beek beka beke daab daad daae daba dabb dada dade daeb daka dake dddd dead deae deak deba debe deda dedd dede deeb deed deek dek- deka deke dkba eaba eada eadb eadd ebba ebed edad edda edde ede- edea eede eeea eeee eeka eeke eka- ekab ekeb eked ekek ekka kaaa kaab kaak kaba kabb kabd kabe kad- kada kadd kade kaka kake kakk kbaa kbab kbad kbae kbak kbba kbbb kbbd kbbe kbbk kbdb kbde kbeb kbed kbee kbek kbkb kbkk kdaa kdab kdad kdae kdak kdbb kddb kddd kddk kdeb kdka kdkb kdkd kdkk kea- kead keak keba kebb kebe keda kedb kedd kede keed keek keka kekb keke kkaa kkba kkbb kkbd kkbe kkda kkdd kkea kked kkkk