a-a a-b a-c aaa aab aac aaj aao ab- aba abb abc abj abo ac- aca acb acc acj aco aja ajb ajc ajj ajo aoa aob aoc aoj aoo baa bab bac baj bao bba bbb bbc bbo bca bcb bcc bcj bco bja bjc bjj boa bob boc boj boo c-- c-j caa cab cac caj cao cba cbb cbc cbj cbo cca ccb ccc ccj cco cja cjb cjc co- coa cob coc coj coo jaa jab jac jaj jao jba jbc jbj jbo jca jcb jcc jco jja jjb jjc jjj joa job joc joj joo oaa oab oac oaj oao ob- oba obb obc obj obo oc- oca ocb occ ocj oco oja ojb ojc ojo oo- ooa oob ooc ooo