-ic a-a a-b a-c a-i aaa aab aac aai aap aas ab- aba abb abc abi abp abs ac- aca acb acc aci acp acs ai- aia aib aic aii aip ais ap- apa apb apc api app aps as- asa asb asc asi asp ass b-p baa bab bac bai bap bas bba bbb bbc bbi bbp bbs bca bcb bcc bci bcp bcs bi- bia bib bic bii bip bis bpa bpb bpc bpi bpp bps bsa bsb bsc bsi bsp bss c-- caa cab cac cai cap cas cba cbb cbc cbi cbp cbs cca ccb ccc cci ccp ccs ci- cia cib cic cii cip cis cpa cpb cpc cpi cpp cps csa csb csc csi csp css ia- iaa iab iac iai iap ias iba ibb ibc ibi ibp ibs ica icb icc ici icp ics iia iib iic iii iip iis ipa ipb ipc ipi ipp ips is- isa isb isc isi isp iss p-p paa pab pac pai pap pas pba pbb pbc pbi pbp pbs pca pcb pcc pci pcp pcs pia pib pic pii pip pis ppa ppb ppc ppi ppp pps ps- psa psb psc psi psp pss saa sab sac sai sap sas sba sbb sbc sbi sbp sbs sca scb scc sci scp scs sia sib sic sii sip sis spa spb spc spi spp sps ss- ssa ssb ssc ssi ssp sss