-er a-a a-c aaa aac aad aae aaf aap aar ac- aca acc acd ace acf acp acr ad- ada adc add ade adf adp adr aea aec aed aee aef aep aer af- afa afc afd afe aff afp afr ap- apa apc apd ape apf app apr ar- ara arc ard are arf arp arr c-- caa cac cad cae caf cap car cca ccc ccd cce ccf ccp ccr cda cdc cdd cde cdf cdp cdr ce- cea cec ced cee cef cep cer cfa cfc cfd cfe cff cfp cfr cpa cpc cpd cpe cpf cpp cpr cra crc crd cre crf crp crr daa dac dad dae daf dap dar dca dcc dcd dce dcf dcp dcr dda ddc ddd dde ddf ddp ddr de- dea dec ded dee def dep der dfa dfc dfd dfe dff dfp dfr dpa dpc dpd dpe dpf dpp dpr dra drc drd dre drp drr eaa eac ead eae eaf eap ear ec- eca ecc ecd ece ecf ecr ed- eda edc edd ede edf edp edr eea eec eed eee eef eep eer ef- efa efc efd efe eff efp efr ep- epa epc epd epe epf epp epr era erc erd ere erf erp err faa fac fad fae faf fap far fca fcc fcd fce fcf fcp fcr fda fdc fdd fde fdf fdp fdr fea fec fed fee fef fep fer ffa ffc ffd ffe fff ffp ffr fpa fpc fpd fpe fpp fpr fra frc frd fre frf frp frr p-p paa pac pad pae paf pap par pca pcc pcd pce pcf pcp pcr pda pdc pdd pde pdf pdp pdr pea pec ped pee pef pep per pfa pfc pfd pfe pff pfp pfr ppa ppc ppd ppe ppf ppp ppr pra prc prd pre prf prp prr ra- raa rac rad rae raf rap rar rca rcc rcd rce rcf rcp rcr rda rdc rdd rde rdf rdp rdr re- rea rec red ree ref rep rer rfa rfc rfd rfe rff rfp rfr rpa rpc rpd rpe rpf rpp rpr rra rrc rrd rrf rrp rrr