COC(=O)c1cc(NC(=O)c2cc(NC(=O)c3cc([N+](=O)[O-])cn3C)cn2C)cn1C
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?