a-ak a-ha aaaa aaab aaac aaah aaba aabb aabc aabh aaca aacb aacc aach aack aaha aahk aaka abaa abab abac abak abb- abba abbb abca abcb abcc abch abha acaa acab acac acba acca accc acch acha achh ahab ahac ahah ahha akaa akah akca akha akka baaa baah baak baba babb bac- baca bacc bach back baha bak- baka bakh bbbb bbch bcaa bcbc bcca bccc bhca bhcc caaa caab caac caah caba cac- caca cacc cach cack caha caka cbac cbbc cbca cbcc cbha cbka ccaa ccab ccac ccba ccbc ccca cccb cccc ccha chaa chab chac chah chak chca chch chha chka chkb ckac ckbc ckch ckck haab haak haba hack haha haka hakk hcbc hcca hccb hccc hcch hhaa hhhh hkcc kaaa kaab kaak kaba kabb kabc kacb kacc kach kaha kahc kaka kakc kakh kakk kbaa kbab kbac kbak kbba kbbb kbbc kbbk kbca kbcb kbch kbck kbhb kbhc kbhh kbkb kbkk kcaa kcab kcac kcah kcba kcbc kcbk kcca kccb kccc kcck kcha kchh kchk kckc kckk khab khac khak khbc khca khcb khcc khch khck khhk khka khkk kkaa kkac kkba kkbb kkcb kkch kkck kkha kkhb kkhh kkhk kkkk