CCC(=O)OC[n+]1ccc2c(C)c3[nH]c4ccccc4c3c(C)c2c1.[I-]
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. Amide C-N bonds are not counted because of their high barrier to rotation.  How many rotatable bonds does the molecule have?