a-a a-c aaa aac aad aap aar ac- aca acc acd acp acr ad- ada adc add adp adr ap- apa apc apd app apr ar- ara arc ard arp arr c-- caa cac cad cap car cca ccc ccd ccp ccr cda cdc cdd cdp cdr cpa cpc cpd cpp cpr cra crc crd crp crr daa dac dad dap dar dca dcc dcd dcp dcr dda ddc ddd ddp ddr dpa dpc dpd dpp dpr dra drc drd drp drr p-p paa pac pad pap par pca pcc pcd pcp pcr pda pdc pdd pdp pdr ppa ppc ppd ppp ppr pra prc prd prp prr ra- raa rac rad rap rar rca rcc rcd rcp rcr rda rdc rdd rdp rdr rpa rpc rpd rpp rpr rra rrc rrd rrp rrr