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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def backward(self,pixx,pixy):
 """ Transform pixx,pixy positions from the output frame back onto their original positions in the input frame. """

        skyx,skyy = self.output.wcs_pix2world(pixx,pixy,self.origin)
        result = self.input.all_world2pix(skyx,skyy,self.origin)
        return result