Br.O=C1c2ccccc2C(=O)N1c1cccc(-c2csc(Nc3ccc4c(c3)OCO4)n2)c1
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?