import GHC.Show (Show(..), ShowS,
shows, showString, showChar, showParen)
import GHC.Err (undefined)
-import GHC.Num (Integer, fromInteger, (+))
+import GHC.Num (Integer, (+))
import GHC.Real ( rem, Ratio )
import GHC.IORef (IORef,newIORef)
import GHC.IO (unsafePerformIO,mask_)