aaaa aaab aaac aaad aaal aaba aabb aabc aabd aabl aaca aacb aacc aacd aacl aada aadc aala aalc aald aall abaa abab abac abad abal abb- abba abbb abca abcb abcc abcd abcl abda abla acaa acab acac acad acba acbl acca accc accd acda acdb acdc acla aclc adaa adab adac adad adal adba adbc adcc adda addc addd addl alaa alac alad alal alb- alba albc alca alcc ald- alda aldl all- alla alll baaa baad baal baba babb bac- baca bacc bada badb badd bala balc bald ball bbad bbbb bbdd bblb bcaa bcbc bcca bccc bccl bcda bdbc bddc blaa blab blac blad bldc c-cd caaa caab caac caal caba cac- caca cacc cada cadc cadd cala calc cald call cbac cbal cbbc cbca cbcc cbcl cbdb cbdc cblb cblc ccaa ccab ccac ccad ccba ccbc ccca cccb cccc cccl ccdc ccla cclc cdaa cdac cdad cdba cdda cddb cddl clab clad clcd cldc daab daad daal daba dabb daca dada dala dall dbcc dcbc dcca dccb dccc dccl dcdb dddd ddlc dlab dlbd laaa laac laad laal laba laca lacc lacl lada ladd lala lald lall lbcc lcac lcad lcbc lcca lccc lcdd llcc lldb lldc lllc llll