-er -ic bbb bbc bbe bbi bbr bbt bcb bcc bce bci bcr bct bcv be- beb bec bee bei ber bet bev bi- bib bic bie bii bir bit biv brb bre bri brr brt brv btb btc bte bti btr btt btv bvb bvc bve bvi bvr bvt bvv c-- cbb cbc cbe cbi cbr cbt cbv ccb ccc cce cci ccr cct ccv ce- ceb cec cee cei cer cet cev ci- cib cic cie cii cir cit civ crb crc cre cri crr crt crv ctb ctc cte cti ctr ctt ctv cvb cvc cve cvi cvr cvt cvv ebb ebc ebe ebi ebr ebt ebv ec- ecb ecc ece eci ecr ect ecv eeb eec eee eer eet eev eib eic eie eii eir eit eiv erb erc ere eri err ert erv etb etc ete eti etr ett etv evb evc eve evi evr evt evv i-v ibb ibc ibe ibi ibr ibt ibv icb icc ice ici icr ict icv ie- iec iee iei ier iet iev iib iic iie iii iir iit ir- irb irc ire iri irr irt irv itb itc ite iti itt itv ivb ivc ive ivi ivr ivt ivv rbb rbc rbe rbi rbr rbt rcb rcc rce rci rcr rct rcv re- reb rec ree rei rer ret rev rib ric rie rii rir rit riv rrb rrc rri rrr rrt rtb rtc rte rti rtr rtt rtv rvb rvc rve rvi rvr rvt rvv tbb tbc tbe tbi tbr tbt tbv tcb tcc tce tci tcr tct tcv te- teb tec tee tei ter tet tev tib tic tie tii tir tit tiv trb trc tre tri trr trt trv ttb ttc tte tti ttr ttt ttv tvb tvc tve tvi tvr tvt v-e vbc vbi vbr vbv vcc vce vci vcr vct veb vec vee vei ver vet vi- vib vic vie vii vir vit viv vrb vrc vre vri vrr vrt vtb vtc vte vti vtr vtt vtv vvb vvc vvi vvr vvt vvv