a-a a-b aaa aab aad aag aar ab- aba abb abd abg abr ad- ada adb add adg adr ag- aga agb agd agg agr ar- ara arb ard arg arr baa bab bad bag bar bba bbb bbd bbg bbr bda bdb bdd bdg bdr bga bgb bgd bgg bgr bra brb brd brg brr daa dab dad dag dar dba dbb dbd dbg dbr dda ddb ddd ddg ddr dga dgd dgg dgr dra drb drd drg drr g-d gaa gab gad gag gar gba gbd gbg gbr gda gdb gdd gdr gga ggb ggd ggg ggr gra grb grd grg grr ra- raa rab rad rag rar rba rbb rbd rbg rbr rda rdb rdd rdg rdr rga rgb rgd rgg rgr rra rrb rrd rrg rrr