-er bbb bbe bbg bbr bbs be- beb bee beg ber bes bgb bge bgg bgr bgs brb bre brg brr brs bsb bse bsg bsr bss ebb ebe ebg ebr ebs eeb eee eeg eer ees egb ege egg egr egs erb ere erg err ers es- esb ese esg esr ess gbe gbg gbr gbs ge- geb gee geg ger ges ggb ggg ggr ggs grb gre grg grr grs gsb gse gsg gsr gss rbb rbe rbg rbr rbs re- reb ree reg rer res rgb rge rgg rgr rgs rrb rrg rrr rrs rsb rse rsg rsr rss sbb sbe sbg sbr sbs se- seb see seg ser ses sgb sge sgg sgr sgs sr- srb sre srg srr srs ss- ssb sse ssg ssr sss