-er b-u bbb bbe bbg bbr bbu be- beb bee beg ber beu bez bgb bge bgg bgr bgu bgz brb bre brg brr bru brz bub bue bug bur buu buz bze bzr bzu bzz ebb ebe ebg ebr ebu eeb eee eeg eer egb ege egg egr egu erb ere erg err eru erz eu- eub eue eug eur eze ezr ezz gbe gbg gbr gbu gbz ge- geb gee geg ger geu gez ggb ggg ggr ggu ggz grb gre grg grr gru gu- gub gue gug gur guu guz gzr gzu rbb rbe rbg rbr rbu re- reb ree reg rer reu rez rgb rge rgg rgr rrb rrg rrr rru rub rue rug rur ruu ruz rzb rze ubb ube ubg ubr ubu ueb uee ueg uer ugb uge ugg ugr ugu ur- urb ure urg urr uru urz uue uug uur uuu uzb uzu z-g zbb zbr zeb zee zer zez zgb zgg zub zug zur zuz zzr zzz