-er -ic a-a a-b a-c a-i aaa aab aac aae aai aao aap aar ab- aba abb abc abe abi abo abp abr ac- aca acb acc ace aci aco acp acr aea aeb aec aee aei aeo aep aer ai- aia aib aic aie aii aio aip air aoa aob aoc aoe aoi aoo aop aor ap- apa apb apc ape api apo app apr ar- ara arb arc are ari aro arp arr b-p baa bab bac bae bai bao bap bar bba bbb bbc bbe bbi bbo bbp bbr bca bcb bcc bce bci bco bcp bcr be- bea beb bec bee bei beo bep ber bi- bia bib bic bie bii bio bip bir boa bob boc boe boi boo bop bor bpa bpb bpc bpe bpi bpo bpp bpr bra brb bre bri bro brp brr c-- caa cab cac cae cai cao cap car cba cbb cbc cbe cbi cbo cbp cbr cca ccb ccc cce cci cco ccp ccr ce- cea ceb cec cee cei ceo cep cer ci- cia cib cic cie cii cio cip cir co- coa cob coc coe coi coo cop cor cpa cpb cpc cpe cpi cpo cpp cpr cra crb crc cre cri cro crp crr eaa eab eac eae eai eao eap ear eba ebb ebc ebe ebi ebo ebp ebr ec- eca ecb ecc ece eci eco ecr eea eeb eec eee eeo eep eer eia eib eic eie eii eio eip eir eo- eoa eob eoc eoe eoi eoo eop eor ep- epa epb epc epe epi epo epp epr era erb erc ere eri ero erp err ia- iaa iab iac iae iai iao iap iar iba ibb ibc ibe ibi ibo ibp ibr ica icb icc ice ici ico icp icr ie- iea iec iee iei iep ier iia iib iic iie iii iio iip iir io- ioa iob ioc ioe ioi ioo iop ior ipa ipb ipc ipe ipi ipo ipp ipr ir- ira irb irc ire iri iro irp irr o-i oaa oab oac oae oai oao oap oar ob- oba obb obc obe obi obo obp obr oc- oca ocb occ oci oco ocp ocr oea oeb oec oee oei oeo oep oer oia oib oic oie oii oio oip oir oo- ooa oob ooc ooi ooo oop oor op- opa opb opc ope opi opo opp opr or- ora orb orc ore ori oro orp orr p-p paa pab pac pae pai pao pap par pba pbb pbc pbe pbi pbo pbp pbr pca pcb pcc pce pci pco pcp pcr pea peb pec pee pei peo pep per pia pib pic pie pii pio pip pir poa pob poc poe poi poo pop por ppa ppb ppc ppe ppi ppo ppp ppr pra prb prc pre pri pro prp prr ra- raa rab rac rae rai rao rap rar rba rbb rbc rbe rbi rbo rbp rbr rca rcb rcc rce rci rco rcp rcr re- rea reb rec ree rei reo rep rer ria rib ric rie rii rio rip rir roa rob roc roe roi roo rop ror rpa rpb rpc rpe rpi rpo rpp rpr rra rrb rrc rri rrp rrr