-ic a-a a-b a-c a-i aaa aab aac aai aak aap ab- aba abb abc abi abk abp ac- aca acb acc aci ack acp ai- aia aib aic aii aik aip aka akb akc aki akk akp ap- apa apb apc api apk app b-p baa bab bac bai bak bap bba bbb bbc bbi bbk bbp bca bcb bcc bci bck bcp bi- bia bib bic bii bik bip bka bkb bkc bkk bkp bpa bpb bpc bpi bpp c-- caa cab cac cai cak cap cba cbb cbc cbi cbk cbp cca ccb ccc cci cck ccp ci- cia cib cic cii cik cip cka ckb ckc cki cpa cpb cpc cpi cpk cpp ia- iaa iab iac iai iap iba ibb ibc ibi ibk ibp ica icb icc ici ick icp iia iib iic iii iip ika ikb ikc iki ikk ipa ipb ipc ipi ipp ka- kaa kab kac kai kak kap kba kbb kbc kbi kbk kbp kca kcb kcc kci kck kcp kia kib kic kii kik kip kkb kkc kki kkk kkp kpa kpc kpi kpk kpp p-p paa pab pac pai pak pap pba pbb pbc pbi pbk pbp pca pcb pcc pci pck pcp pia pib pic pii pik pip pka pkb pkc pki pkp ppa ppb ppc ppi ppk ppp