COc1ccc(C2C3=C(N=C4SC(C(C)=O)=C(C)N42)c2ccccc2CC3)cc1
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?