-er bbb bbe bbi bbr be- beb bee bei ber bev bi- bib bie bii bir biv brb bre bri brr brv bvb bve bvi bvr bvv ebb ebe ebi ebr ebv eeb eee eer eev eib eie eii eir eiv erb ere eri err erv evb eve evi evr evv i-v ibb ibe ibi ibr ibv ie- iee iei ier iev iib iie iii iir ir- irb ire iri irr irv ivb ive ivi ivr ivv rbb rbe rbi rbr re- reb ree rei rer rev rib rie rii rir riv rrb rri rrr rvb rve rvi rvr rvv v-e vbi vbr vbv veb vee vei ver vi- vib vie vii vir viv vrb vre vri vrr vvb vvi vvr vvv