a-a a-b a-q aaa aab aag aaq aar ab- aba abb abg abq abr ag- aga agb agg agq agr aqa aqr ar- ara arb arg arq arr baa bab bag baq bar bba bbb bbg bbq bbr bga bgb bgg bgr bra brb brg brq brr gaa gab gag gar gba gbg gbr gga ggb ggg ggr gra grb grg grq grr qaa qag qar qba qbq qga qqq qra qrb qrg ra- raa rab rag raq rar rba rbb rbg rbr rga rgb rgg rgr rra rrb rrg rrq rrr