NC(=O)Cn1cc(-c2cc(-c3cc4ccccc4s3)c3[nH]ncc3c2)c2nc(N)ncc21
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?