Cc1c(C)c2c(OCC(=O)NC3CC3)cc3c(c2oc1=O)CCC(C)(C)O3
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?