c-- ccc ccd cce ccf ccn cdc cdd cde cdf cdn ce- cec ced cee cef cen cfc cfd cfe cff cfn cn- cnc cnd cne cnf cnn dcc dcd dce dcf dcn ddc ddd dde ddf ddn de- dec ded dee def den dfc dfd dfe dff dfn dnc dnd dne dnf dnn ec- ecc ecd ece ecf ecn ed- edc edd ede edf edn eec eed eee eef een ef- efc efd efe eff en- enc end ene enf enn fcc fcd fce fcf fcn fdc fdd fde fdf fdn fec fed fee fef fen ffc ffd ffe fff ffn fnc fnd fne fnf fnn ncc ncd nce ncf ncn ndc ndd nde ndf ndn ne- nec ned nee nef nen nfc nfd nfe nff nfn nnc nne nnf nnn