O=C1CSC(c2ccccc2O)N1c1nc2cc3sc(N4C(=O)CSC4c4ccccc4O)nc3cc2s1
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?