mkcb kmcb mckb cmkb kcmb ckmb mkbc kmbc mbkc bmkc kbmc bkmc mcbk cmbk mbck bmck cbmk bcmk kcbm ckbm kbcm bkcm cbkm bckm
Note: these 'words' (valid or invalid) are all the permutations of the word mkcb. These words are obtained by scrambling the letters in mkcb.