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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 find_top_level_complex(gpr):
 """ Find unique elements of both branches of the top level logical AND. Parameters gpr : str The gene-protein-reaction association as a string. Returns ------- int The size of the symmetric difference between the set of elements to the left of the top level logical AND and the right set. """

    logger.debug("%r", gpr)
    conform = logical_and.sub("and", gpr)
    conform = logical_or.sub("or", conform)
    conform = escape_chars.sub("_", conform)
    expression = ast.parse(conform)
    walker = GPRVisitor()
    walker.visit(expression)
    return len(walker.left ^ walker.right)