a-ak a-be a-ok aaaa aaab aaae aaba aabb aaea aaka aake aaoe aaoo abaa abab abae abak abb- abba abbb abbe abbo abee aboa abob abok aboo aeka akaa akae akao akee akka akko akok aoba baaa baak baba babb babe babo baek bak- baka bake bako bbbb bbeb beak beba bebb bebe bebo beeb beek beka beke beko beo- beok boab boak boba bobb bobe bobo boea boee boeo boka boke boko boob booe book eaba ebba ebbo eboe eboo eeea eeee eeka eeke eka- ekab ekeb ekek ekka ekoa eoka kaaa kaab kaak kaba kabb kabe kabo kaeo kaka kake kakk kako kaoa kaok kbaa kbab kbae kbak kbba kbbb kbbe kbbk kbbo kbeb kbee kbek kbeo kbkb kbkk kbko kboa kbob kboe kbok kboo kea- keak keba kebb kebe keek keka kekb keke keko keok kkaa kkba kkbb kkbe kkbo kkea kkkk kkoa kkob kkoo koab koae koak koba kobb kobe kobk kobo koea koka kokb koke kokk koko koob kook kooo o-eo oake obak obba obbo obea obkb oboe obok okak okka okko okok ooaa ooak ooba oobe oooo