a-a a-b a-t aaa aab aad aak aao aat ab- aba abb abd abk abo abt ad- ada adb add adk ado adt aka akb akd akk ako aoa aob aod aok aoo aot at- ata atb atd ato att baa bab bad bak bao bat bba bbb bbd bbk bbo bbt bda bdb bdd bdk bdo bdt bka bkb bkk bko bkt boa bob bod bok boo bot bta btb btd btk bto btt daa dab dad dak dao dat dba dbb dbd dbk dbo dbt dda ddb ddd ddk ddo ddt dka dkb dkk dko dkt doa dob dod dok doo dot dta dtb dtd dtk dto dtt k-t ka- kaa kab kad kak kao kat kba kbb kbd kbk kbo kda kdb kdk kdo kdt kkb kkk kkt koa kob kod kok koo kot kta ktb ktk kto ktt oaa oab oad oak oao oat ob- oba obb obd obk obo obt oda odb odd odo odt oka okb okd okk oko oo- ooa oob ood ook ooo oot ot- ota otb otd otk oto ott taa tab tad tak tao tat tba tbb tbd tbk tbo tbt tda tdb tdd tdk tdo tdt tka tkb tkk tko tkt to- toa tob tod tok too tot tta ttb ttd ttk tto ttt