Cn1c(=O)n2n(c1=O)C(C)(C13CC4CC(CC(C4)C1)C3)C13CC4CC(CC1C4)CC23
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?