-er -ic a-a a-b a-c a-i aaa aab aac aae aai aao aap aar aas ab- aba abb abc abe abi abo abp abr abs ac- aca acb acc ace aci aco acp acr acs aea aeb aec aee aei aeo aep aer aes ai- aia aib aic aie aii aio aip air ais aoa aob aoc aoe aoi aoo aop aor aos ap- apa apb apc ape api apo app apr aps ar- ara arb arc are ari aro arp arr ars as- asa asb asc ase asi aso asp asr ass b-p baa bab bac bae bai bao bap bar bas bba bbb bbc bbe bbi bbo bbp bbr bbs bca bcb bcc bce bci bco bcp bcr bcs be- bea beb bec bee bei beo bep ber bes bi- bia bib bic bie bii bio bip bir bis boa bob boc boe boi boo bop bor bos bpa bpb bpc bpe bpi bpo bpp bpr bps bra brb bre bri bro brp brr brs bsa bsb bsc bse bsi bso bsp bsr bss c-- caa cab cac cae cai cao cap car cas cba cbb cbc cbe cbi cbo cbp cbr cbs cca ccb ccc cce cci cco ccp ccr ccs ce- cea ceb cec cee cei ceo cep cer ces ci- cia cib cic cie cii cio cip cir cis co- coa cob coc coe coi coo cop cor cos cpa cpb cpc cpe cpi cpo cpp cpr cps cra crb crc cre cri cro crp crr crs csa csb csc cse csi cso csp csr css eaa eab eac eae eai eao eap ear eas eba ebb ebc ebe ebi ebo ebp ebr ebs ec- eca ecb ecc ece eci eco ecr ecs eea eeb eec eee eeo eep eer ees eia eib eic eie eii eio eip eir eis eo- eoa eob eoc eoe eoi eoo eop eor eos ep- epa epb epc epe epi epo epp epr eps era erb erc ere eri ero erp err ers es- esa esb esc ese esi eso esp esr ess ia- iaa iab iac iae iai iao iap iar ias iba ibb ibc ibe ibi ibo ibp ibr ibs ica icb icc ice ici ico icp icr ics ie- iea iec iee iei iep ier ies iia iib iic iie iii iio iip iir iis io- ioa iob ioc ioe ioi ioo iop ior ios ipa ipb ipc ipe ipi ipo ipp ipr ips ir- ira irb irc ire iri iro irp irr irs is- isa isb isc ise isi iso isp isr iss o-i oaa oab oac oae oai oao oap oar oas ob- oba obb obc obe obi obo obp obr obs oc- oca ocb occ oci oco ocp ocr ocs oea oeb oec oee oei oeo oep oer oes oia oib oic oie oii oio oip oir ois oo- ooa oob ooc ooi ooo oop oor oos op- opa opb opc ope opi opo opp opr ops or- ora orb orc ore ori oro orp orr ors os- osa osb osc ose osi oso osp osr oss p-p paa pab pac pae pai pao pap par pas pba pbb pbc pbe pbi pbo pbp pbr pbs pca pcb pcc pce pci pco pcp pcr pcs pea peb pec pee pei peo pep per pes pia pib pic pie pii pio pip pir pis poa pob poc poe poi poo pop por pos ppa ppb ppc ppe ppi ppo ppp ppr pps pra prb prc pre pri pro prp prr prs ps- psa psb psc pse psi pso psp psr pss ra- raa rab rac rae rai rao rap rar ras rba rbb rbc rbe rbi rbo rbp rbr rbs rca rcb rcc rce rci rco rcp rcr rcs re- rea reb rec ree rei reo rep rer res ria rib ric rie rii rio rip rir ris roa rob roc roe roi roo rop ror ros rpa rpb rpc rpe rpi rpo rpp rpr rps rra rrb rrc rri rrp rrr rrs rsa rsb rsc rse rsi rso rsp rsr rss saa sab sac sae sai sao sap sar sas sba sbb sbc sbe sbi sbo sbp sbr sbs sca scb scc sce sci sco scp scr scs se- sea seb sec see sei seo sep ser ses sia sib sic sie sii sio sip sir sis soa sob soc soe soi soo sop sor sos spa spb spc spe spi spo spp spr sps sr- sra srb src sre sri sro srp srr srs ss- ssa ssb ssc sse ssi sso ssp ssr sss