O=C1c2ccccc2C(=O)c2c1nc1ccccc1c2-c1cncc(-c2c3c(nc4ccccc24)C(=O)c2ccccc2C3=O)c1
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. How many bonds in the molecule are rotatable?