-al -ol a-a a-b a-c aaa aab aac aal aao aav ab- aba abb abc abl abo abv ac- aca acb acc acl aco acv al- ala alb alc all alo alv aoa aob aoc aol aoo aov av- ava avb avc avl avo baa bab bac bal bao bav bba bbb bbc bbl bbo bca bcb bcc bcl bco bcv bla blb blc bll blo blv boa bob boc bol boo bov bva bvb bvc bvl bvo bvv c-- caa cab cac cal cao cav cba cbb cbc cbl cbo cbv cca ccb ccc ccl cco ccv cl- cla clb clc cll clo clv co- coa cob coc col coo cov cva cvb cvc cvl cvo cvv la- laa lab lac lal lao lav lba lbb lbc lbl lbo lbv lca lcb lcc lcl lco lcv lla llb llc lll llo llv loa lob loc lol loo lov lva lvb lvc lvl lvv oaa oab oac oal oao oav ob- oba obb obc obl obo obv oc- oca ocb occ ocl oco ocv ola olb olc oll olo oo- ooa oob ooc ool ooo oov ov- ova ovb ovc ovl ovo ovv v-a vaa vab vac val vao vav vba vbc vbl vbo vbv vca vcc vcl vco vl- vla vlb vlc vll vlo vlv voa vob voc vol voo vov vva vvb vvc vvo vvv