-er -ic b-p bbb bbc bbe bbi bbp bbr bbs bbt bcb bcc bce bci bcp bcr bcs bct be- beb bec bee bei bep ber bes bet bi- bib bic bie bii bip bir bis bit bpb bpc bpe bpi bpp bpr bps bpt brb bre bri brp brr brs brt bsb bsc bse bsi bsp bsr bss bst btb btc bte bti btp btr bts btt c-- cbb cbc cbe cbi cbp cbr cbs cbt ccb ccc cce cci ccp ccr ccs cct ce- ceb cec cee cei cep cer ces cet ci- cib cic cie cii cip cir cis cit cpb cpc cpe cpi cpp cpr cps cpt crb crc cre cri crp crr crs crt csb csc cse csi csp csr css cst ctb ctc cte cti ctp ctr cts ctt ebb ebc ebe ebi ebp ebr ebs ebt ec- ecb ecc ece eci ecr ecs ect eeb eec eee eep eer ees eet eib eic eie eii eip eir eis eit ep- epb epc epe epi epp epr eps ept erb erc ere eri erp err ers ert es- esb esc ese esi esp esr ess est etb etc ete eti etp etr ets ett ibb ibc ibe ibi ibp ibr ibs ibt icb icc ice ici icp icr ics ict ie- iec iee iei iep ier ies iet iib iic iie iii iip iir iis iit ipb ipc ipe ipi ipp ipr ips ipt ir- irb irc ire iri irp irr irs irt is- isb isc ise isi isp isr iss ist itb itc ite iti itp its itt p-p pbb pbc pbe pbi pbp pbr pbs pbt pcb pcc pce pci pcp pcr pcs pct peb pec pee pei pep per pes pet pib pic pie pii pip pir pis pit ppb ppc ppe ppi ppp ppr pps ppt prb prc pre pri prp prr prs prt ps- psb psc pse psi psp psr pss pst pt- ptb ptc pte pti ptp ptr pts ptt rbb rbc rbe rbi rbp rbr rbs rbt rcb rcc rce rci rcp rcr rcs rct re- reb rec ree rei rep rer res ret rib ric rie rii rip rir ris rit rpb rpc rpe rpi rpp rpr rps rpt rrb rrc rri rrp rrr rrs rrt rsb rsc rse rsi rsp rsr rss rst rtb rtc rte rti rtp rtr rts rtt sbb sbc sbe sbi sbp sbr sbs sbt scb scc sce sci scp scr scs sct se- seb sec see sei sep ser ses set sib sic sie sii sip sir sis sit spb spc spe spi spp spr sps spt sr- srb src sre sri srp srr srs srt ss- ssb ssc sse ssi ssp ssr sss sst stb stc ste sti stp str sts stt tbb tbc tbe tbi tbp tbr tbs tbt tcb tcc tce tci tcp tcr tcs tct te- teb tec tee tei tep ter tes tet tib tic tie tii tip tir tis tit tpb tpc tpe tpi tpp tpr tps tpt trb trc tre tri trp trr trs trt tsb tsc tse tsi tsp tsr tss tst ttb ttc tte tti ttp ttr tts ttt