bbb bbd bbe bbk bbo bdb bdd bde bdk bdo be- beb bed bee bek beo bkb bke bkk bko bob bod boe bok boo dbb dbd dbe dbk dbo ddb ddd dde ddk ddo de- deb ded dee dek deo dkb dke dkk dko dob dod doe dok doo ebb ebd ebe ebk ebo ed- edb edd ede edk edo eeb eed eee eek eeo ekb ekd eke eko eo- eob eod eoe eok eoo kbb kbd kbe kbk kbo kdb kde kdk kdo ke- keb ked kee kek keo kkb kke kkk kob kod koe kok koo ob- obb obd obe obk obo odb odd ode odo oeb oed oee oeo okb okd oke okk oko oo- oob ood ook ooo