c1cc(CNC2C3CCC(C3)C2c2c[nH]c3ccccc23)cc(CNC2C3CCC(C3)C2c2c[nH]c3ccccc23)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?