-er a-a a-b aaa aab aae aag aak aar aau ab- aba abb abe abg abk abr abu aea aeb aee aeg aek aer aeu ag- aga agb age agg agk agr agu aka akb ake akg akk akr aku ar- ara arb are arg ark arr aru au- aua aub aue aug auk aur b-u baa bab bae bag bak bar bau bba bbb bbe bbg bbk bbr bbu be- bea beb bee beg bek ber beu bga bgb bge bgg bgk bgr bgu bka bkb bke bkg bkk bkr bra brb bre brg brk brr bru bua bub bue bug buk bur buu eaa eab eae eag eak ear eau eba ebb ebe ebg ebk ebr ebu eea eeb eee eeg eek eer ega egb ege egg egr egu eka ekb eke ekg ekr eku era erb ere erg erk err eru eu- eua eub eue eug eur gaa gab gae gag gak gar gau gba gbe gbg gbk gbr gbu ge- gea geb gee geg gek ger geu gga ggb ggg ggr ggu gka gkb gra grb gre grg grk grr gru gu- gua gub gue gug guk gur guu ka- kaa kab kae kag kak kar kau kba kbb kbe kbk kbr kbu ke- kea keb kee keg kek ker kga kgb kgu kkb kke kkk kkr kku kra krg krk krr kru kub kue kug kuk kur kuu ra- raa rab rae rag rak rar rau rba rbb rbe rbg rbk rbr rbu re- rea reb ree reg rek rer reu rga rgb rge rgg rgk rgr rkb rke rkg rkk rku rra rrb rrg rrk rrr rru rua rub rue rug ruk rur ruu ua- uaa uab uae uag uak uar uau uba ubb ube ubg ubk ubr ubu uea ueb uee ueg uer uga ugb uge ugg ugk ugr ugu uka ukb uke ukk ukr uku ur- ura urb ure urg urk urr uru uua uue uug uur uuu