a-a a-b a-c aaa aab aac aad aao aaw ab- aba abb abc abd abo abw ac- aca acb acc acd aco acw ad- ada adb adc add ado adw aoa aob aoc aod aoo aow aw- awa awb awc awd awo aww baa bab bac bad bao baw bba bbb bbc bbd bbo bbw bca bcb bcc bcd bco bda bdb bdc bdd bdo bdw boa bob boc bod boo bow bwa bwb bwc bwd bwo c-- caa cab cac cad cao caw cba cbb cbc cbd cbo cbw cca ccb ccc ccd cco ccw cda cdb cdc cdd cdo cdw co- coa cob coc cod coo cow cw- cwa cwb cwc cwd cwo daa dab dac dad dao daw dba dbb dbc dbd dbo dca dcb dcc dcd dco dcw dda ddb ddc ddd ddo ddw doa dob doc dod doo dow dwa dwb dwc dwo dww oaa oab oac oad oao oaw ob- oba obb obc obd obo obw oc- oca ocb occ ocd oco ocw oda odb odc odd odo oo- ooa oob ooc ood ooo oow owa owb owc owd owo oww waa wab wac wad wao waw wba wbb wbc wbd wbo wbw wca wcb wcc wcd wco wcw wda wdb wdc woa wob woc wod woo wow wwa wwc wwd wwo www