-ic c-- ccc ccd cci ccs ccx cdc cdd cdi cds cdx ci- cic cid cii cis cix csc csd csi css csx cxc cxi cxs cxx dcc dcd dci dcs dcx ddc ddd ddi dds ddx di- dic did dii dis dix dsc dsd dsi dss dsx dxc dxd dxi dxs dxx i-d icc icd ici ics idc idd idi ids idx iic iid iii iis iix is- isc isd isi iss ixc ixi scc scd sci scs scx sdc sdd sdi sds sic sid sii sis six ss- ssc ssd ssi sss ssx sxc sxi sxs xcd xci xcx xdc xdi xds xic xii xis xix xsc xsi xss xxi xxx