-er a-a a-c aaa aac aad aae aaf aak aar ac- aca acc acd ace acf ack acr ad- ada adc add ade adf adk adr aea aec aed aee aef aek aer af- afa afc afd afe aff afk afr aka akc akd ake akk akr ar- ara arc ard are arf ark arr c-- caa cac cad cae caf cak car cca ccc ccd cce ccf cck ccr cda cdc cdd cde cdf cdk cdr ce- cea cec ced cee cef cek cer cfa cfc cfd cfe cff cfk cfr cka ckc ckd cra crc crd cre crf crk crr daa dac dad dae daf dak dar dca dcc dcd dce dcf dck dcr dda ddc ddd dde ddf ddk ddr de- dea dec ded dee def dek der dfa dfc dfd dfe dff dfk dfr dka dkc dke dkk dkr dra drc drd dre drk drr eaa eac ead eae eaf eak ear ec- eca ecc ecd ece ecf eck ecr ed- eda edc edd ede edf edk edr eea eec eed eee eef eek eer ef- efa efc efd efe eff efr eka ekc ekd eke ekf ekr era erc erd ere erf erk err faa fac fad fae faf fak far fca fcc fcd fce fcf fck fcr fda fdc fdd fde fdf fdk fdr fea fec fed fee fef fek fer ffa ffc ffd ffe fff ffk ffr fka fkc fkf fkk fra frc frd fre frf frk frr ka- kaa kac kad kae kaf kak kar kca kcc kcd kce kck kcr kda kdc kde kdf kdk kdr ke- kea kec ked kee kef kek ker kfa kfc kfd kff kkc kke kkk kkr kra krc krd krf krk krr ra- raa rac rad rae raf rak rar rca rcc rcd rce rcf rcr rda rdc rdd rde rdf rdr re- rea rec red ree ref rek rer rfa rfc rfd rfe rff rfk rfr rkc rke rkf rkk rra rrc rrd rrf rrk rrr