a-a a-b aaa aab aak aao aaw ab- aba abb abk abo abw aka akb akk ako akw aoa aob aok aoo aow aw- awa awb awk awo aww baa bab bak bao baw bba bbb bbk bbo bbw bka bkb bkk bko bkw boa bob bok boo bow bwa bwb bwk bwo ka- kaa kab kak kao kaw kba kbb kbk kbo kbw kkb kkk koa kob kok koo kow kw- kwa kwk kwo kww oaa oab oak oao oaw ob- oba obb obk obo obw oka okb okk oko okw oo- ooa oob ook ooo oow owa owb owk owo oww waa wab wak wao waw wba wbb wbo wbw wka wkb wko wkw woa wob wok woo wow wwa wwo www