CCC(CO)N1C(C)=CC(=Cc2sc3ccccc3[n+]2Cc2ccccc2)C=C1C.[Br-]
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?