-er -ic bbb bbc bbe bbi bbo bbr bcb bcc bce bci bco bcr be- beb bec bee bei beo ber bi- bib bic bie bii bio bir bob boc boe boi boo bor brb bre bri bro brr c-- cbb cbc cbe cbi cbo cbr ccb ccc cce cci cco ccr ce- ceb cec cee cei ceo cer ci- cib cic cie cii cio cir co- cob coc coe coi coo cor crb crc cre cri cro crr ebb ebc ebe ebi ebo ebr ec- ecb ecc ece eci eco ecr eeb eec eee eeo eer eib eic eie eii eio eir eo- eob eoc eoe eoi eoo eor erb erc ere eri ero err ibb ibc ibe ibi ibo ibr icb icc ice ici ico icr ie- iec iee iei ier iib iic iie iii iio iir io- iob ioc ioe ioi ioo ior ir- irb irc ire iri iro irr o-i ob- obb obc obe obi obo obr oc- ocb occ oci oco ocr oeb oec oee oei oeo oer oib oic oie oii oio oir oo- oob ooc ooi ooo oor or- orb orc ore ori oro orr rbb rbc rbe rbi rbo rbr rcb rcc rce rci rco rcr re- reb rec ree rei reo rer rib ric rie rii rio rir rob roc roe roi roo ror rrb rrc rri rrr