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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 combining_search(self):
 """ Searching the path for combining the pair. """

        start = (
            self.get_pair(), 
            (
                self.cube["L"], 
                self.cube["U"], 
                self.cube["F"], 
                self.cube["D"], 
                self.cube["R"], 
                self.cube["B"], 
                ), 
            )
        return sum(path_actions(a_star_search(start, 
                       self.combining_successors, 
                       lambda x: len(x), 
                       self.combining_goal)), Formula())