-er -ic b-p bbb bbc bbd bbe bbi bbp bbr bbs bcb bcc bcd bce bci bcp bcr bcs bdb bdc bdd bde bdi bdp bdr bds be- beb bec bed bee bei bep ber bes bi- bib bic bid bie bii bip bir bis bpb bpc bpd bpe bpi bpp bpr bps brb brd bre bri brp brr brs bsb bsc bsd bse bsi bsp bsr bss c-- cbb cbc cbd cbe cbi cbp cbr cbs ccb ccc ccd cce cci ccp ccr ccs cdb cdc cdd cde cdi cdp cdr cds ce- ceb cec ced cee cei cep cer ces ci- cib cic cid cie cii cip cir cis cpb cpc cpd cpe cpi cpp cpr cps crb crc crd cre cri crp crr crs csb csc csd cse csi csp csr css dbb dbc dbd dbe dbi dbp dbr dbs dcb dcc dcd dce dci dcp dcr dcs ddb ddc ddd dde ddi ddp ddr dds de- deb dec ded dee dei dep der des di- dib dic did die dii dip dir dis dpb dpc dpd dpe dpi dpp dpr dps drb drc drd dre dri drp drr drs dsb dsc dsd dse dsi dsp dsr dss ebb ebc ebd ebe ebi ebp ebr ebs ec- ecb ecc ecd ece eci ecr ecs ed- edb edc edd ede edi edp edr eds eeb eec eed eee eep eer ees eib eic eid eie eii eip eir eis ep- epb epc epd epe epi epp epr eps erb erc erd ere eri erp err ers es- esb esc esd ese esi esp esr ess i-d ibb ibc ibd ibe ibi ibp ibr ibs icb icc icd ice ici icp icr ics idb idc idd ide idi idp idr ids ie- iec ied iee iei iep ier ies iib iic iid iie iii iip iir iis ipb ipc ipd ipe ipi ipp ipr ips ir- irb irc ird ire iri irp irr irs is- isb isc isd ise isi isp isr iss p-p pbb pbc pbd pbe pbi pbp pbr pbs pcb pcc pcd pce pci pcp pcr pcs pdb pdc pdd pde pdi pdp pdr pds peb pec ped pee pei pep per pes pib pic pid pie pii pip pir pis ppb ppc ppd ppe ppi ppp ppr pps prb prc prd pre pri prp prr prs ps- psb psc psd pse psi psp psr pss rbb rbc rbd rbe rbi rbp rbr rbs rcb rcc rcd rce rci rcp rcr rcs rdb rdc rdd rde rdi rdp rdr rds re- reb rec red ree rei rep rer res rib ric rid rie rii rip rir ris rpb rpc rpd rpe rpi rpp rpr rps rrb rrc rrd rri rrp rrr rrs rsb rsc rsd rse rsi rsp rsr rss sbb sbc sbd sbe sbi sbp sbr sbs scb scc scd sce sci scp scr scs sdb sdc sdd sde sdi sdp sdr sds se- seb sec sed see sei sep ser ses sib sic sid sie sii sip sir sis spb spc spd spe spi spp spr sps sr- srb src srd sre sri srp srr srs ss- ssb ssc ssd sse ssi ssp ssr sss