Nc1nnc2n1C(=O)C(C1(C3=Nc4nnc(N)n4C3=O)Cc3ccccc3C1=O)=N2
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?