CCC(C)(C)c1ccc(OCCCC[n+]2cccc(C)c2C)c(C(C)(C)CC)c1.[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?