O=C(O)c1ccc2c(c1)C(=O)N(c1cccc(C(=O)/C=C/c3ccccc3)c1)C2=O
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?