Nc1c([N+](=O)[O-])cc([N+](=O)[O-])c(-c2nnc(-c3c([N+](=O)[O-])cc([N+](=O)[O-])c(N)c3[N+](=O)[O-])s2)c1[N+](=O)[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?