a-a a-c aaa aac aad aaf aao aar ac- aca acc acd acf aco acr ad- ada adc add adf ado adr af- afa afc afd aff afo afr aoa aoc aod aof aoo aor ar- ara arc ard arf aro arr c-- caa cac cad caf cao car cca ccc ccd ccf cco ccr cda cdc cdd cdf cdo cdr cfa cfc cfd cff cfo cfr co- coa coc cod cof coo cor cra crc crd crf cro crr daa dac dad daf dao dar dca dcc dcd dcf dco dcr dda ddc ddd ddf ddo ddr dfa dfc dfd dff dfo dfr doa doc dod dof doo dor dra drc drd dro drr faa fac fad faf fao far fca fcc fcd fcf fco fcr fda fdc fdd fdf fdo fdr ffa ffc ffd fff ffo ffr foa foc fof foo for fra frc frd frf fro frr oaa oac oad oaf oao oar oc- oca occ ocd ocf oco ocr oda odc odd odf odo odr of- ofa ofc ofd off ofo ofr oo- ooa ooc ood oof ooo oor or- ora orc ord orf oro orr ra- raa rac rad raf rao rar rca rcc rcd rcf rco rcr rda rdc rdd rdf rdo rdr rfa rfc rfd rff rfo rfr roa roc rod rof roo ror rra rrc rrd rrf rrr