a-a a-b a-t a-z aaa aab aad aar aat aaz ab- aba abb abd abr abt abz ad- ada adb add adr adt adz ar- ara arb ard arr art arz at- ata atb atd atr att atz az- aza azb azd azt azz baa bab bad bar bat baz bba bbb bbd bbr bbt bda bdb bdd bdr bdt bdz bra brb brd brr brt brz bta btb btd btr btt btz bza bzd bzr bzz daa dab dad dar dat daz dba dbb dbd dbr dbt dbz dda ddb ddd ddr ddt ddz dra drb drd drr drt drz dta dtb dtd dtr dtt dtz dza dzb dzd dzr ra- raa rab rad rar rat raz rba rbb rbd rbr rbt rda rdb rdd rdr rdt rra rrb rrd rrr rrt rta rtb rtd rtr rtt rtz rza rzb taa tab tad tar tat taz tba tbb tbd tbr tbt tbz tda tdb tdd tdr tdt tra trb trd trr trt trz tta ttb ttd ttr ttt tza tzd zaa zab zad zar zat zaz zbb zbr zbt zdt zta ztr zzr zzt zzz