O=C(O)C(=O)O.c1ccc(CN2CCC(N3CCC(N4CCCCCC4)CC3)CC2)cc1
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?