bbb bbd bbe bbo bbt bdb bdd bde bdo bdt be- beb bed bee beo bet bob bod boe boo bot btb btd bte bto btt dbb dbd dbe dbo dbt ddb ddd dde ddo ddt de- deb ded dee deo det dob dod doe doo dot dtb dtd dte dto dtt ebb ebd ebe ebo ebt ed- edb edd ede edo edt eeb eed eee eeo eet eo- eob eod eoe eoo eot etb etd ete eto ett ob- obb obd obe obo obt odb odd ode odo odt oeb oed oee oeo oet oo- oob ood ooo oot ot- otb otd ote oto ott tbb tbd tbe tbo tbt tdb tdd tde tdo tdt te- teb ted tee teo tet to- tob tod toe too tot ttb ttd tte tto ttt