a-a a-c aaa aac aad aan aar ac- aca acc acd acn acr ad- ada adc add adn adr an- ana anc and ann anr ar- ara arc ard arn arr c-- caa cac cad can car cca ccc ccd ccn ccr cda cdc cdd cdn cdr cn- cna cnc cnd cnn cnr cra crc crd crn crr daa dac dad dan dar dca dcc dcd dcn dcr dda ddc ddd ddn ddr dna dnc dnd dnn dnr dra drc drd drn drr naa nac nad nan nar nca ncc ncd ncn ncr nda ndc ndd ndn ndr nna nnc nnn nra nrc nrd nrn nrr ra- raa rac rad ran rar rca rcc rcd rcn rcr rda rdc rdd rdn rdr rna rnc rnd rnn rnr rra rrc rrd rrn rrr