a-a a-c aaa aac aaf aan aao aar ac- aca acc acf acn aco acr af- afa afc aff afn afo afr an- ana anc anf ann ano anr aoa aoc aof aon aoo aor ar- ara arc arf arn aro arr c-- caa cac caf can cao car cca ccc ccf ccn cco ccr cfa cfc cff cfn cfo cfr cn- cna cnc cnf cnn cno cnr co- coa coc cof con coo cor cra crc crf crn cro crr faa fac faf fan fao far fca fcc fcf fcn fco fcr ffa ffc fff ffn ffo ffr fna fnc fnf fnn fnr foa foc fof fon foo for fra frc frf frn fro frr naa nac naf nan nao nar nca ncc ncf ncn nco ncr nfa nfc nff nfn nfo nfr nna nnc nnf nnn nno no- noa noc nof non noo nor nra nrc nrf nrn nro nrr oaa oac oaf oan oao oar oc- oca occ ocf ocn oco ocr of- ofa ofc off ofn ofo ofr on- ona onc onf onn ono onr oo- ooa ooc oof oon ooo oor or- ora orc orf orn oro orr ra- raa rac raf ran rao rar rca rcc rcf rcn rco rcr rfa rfc rff rfn rfo rfr rna rnc rnn rno rnr roa roc rof ron roo ror rra rrc rrf rrn rrr