a-a a-b a-t aaa aab aao aat aaw ab- aba abb abo abt abw aoa aob aoo aot aow at- ata atb ato att atw aw- awa awb awo awt aww baa bab bao bat baw bba bbb bbo bbt bbw boa bob boo bot bow bta btb bto btt btw bwa bwb bwo oaa oab oao oat oaw ob- oba obb obo obt obw oo- ooa oob ooo oot oow ot- ota otb oto ott otw owa owb owo owt oww taa tab tao tat taw tba tbb tbo tbt to- toa tob too tot tow tta ttb tto ttt ttw twa twb two twt tww waa wab wao wat waw wba wbb wbo wbt wbw woa wob woo wot wow wta wtb wto wtt wtw wwa wwo wwt www