COc1ccc(-n2c(=S)[nH]c3cc(C(=O)Nc4ccccc4OC)ccc3c2=O)c(OC)c1
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?