Cc1c(C)c(C)c(-n2c(=O)n(C)c(=O)n2-n2c(=O)n(C)c(=O)n2-c2c(C)c(C)c(C)c(C)c2C)c(C)c1C
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?