a-a a-b aaa aab aag aak aar aau ab- aba abb abg abk abr abu ag- aga agb agg agk agr agu aka akb akg akk akr aku ar- ara arb arg ark arr aru au- aua aub aug auk aur b-u baa bab bag bak bar bau bba bbb bbg bbk bbr bbu bga bgb bgg bgk bgr bgu bka bkb bkg bkk bkr bra brb brg brk brr bru bua bub bug buk bur buu gaa gab gag gak gar gau gba gbg gbk gbr gbu gga ggb ggg ggr ggu gka gkb gra grb grg grk grr gru gu- gua gub gug guk gur guu ka- kaa kab kag kak kar kau kba kbb kbk kbr kbu kga kgb kgu kkb kkk kkr kku kra krg krk krr kru kub kug kuk kur kuu ra- raa rab rag rak rar rau rba rbb rbg rbk rbr rbu rga rgb rgg rgk rgr rkb rkg rkk rku rra rrb rrg rrk rrr rru rua rub rug ruk rur ruu ua- uaa uab uag uak uar uau uba ubb ubg ubk ubr ubu uga ugb ugg ugk ugr ugu uka ukb ukk ukr uku ur- ura urb urg urk urr uru uua uug uur uuu