-er bbb bbe bbo bbr be- beb bee beo ber bez bob boe boo bor boz brb bre bro brr brz bze bzo bzr bzz ebb ebe ebo ebr eeb eee eeo eer eo- eob eoe eoo eor erb ere ero err erz eze ezo ezr ezz ob- obb obe obo obr oeb oee oeo oer oo- oob ooo oor or- orb ore oro orr orz oze ozo ozz rbb rbe rbo rbr re- reb ree reo rer rez rob roe roo ror roz rrb rrr rzb rze rzo zbb zbr zeb zee zeo zer zez zo- zob zoe zoo zor zro zzr zzz