COC(=O)C1(CCC(=O)N(C)c2ccccc2)NNC2C(=O)N(c3ccccc3)C(=O)C21
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?