def special_structures(input_string):
    """
    Replace some special structures by space.
    """
    input_string = input_string.replace("'", " ")
    input_string = input_string.replace("(", " ")
    input_string = input_string.replace(")", " ")
    input_string = input_string.replace("1er ", " ")
    input_string = input_string.replace(",", " ")
    input_string = input_string.replace("«", " ")
    input_string = input_string.replace("»", " ")
    output_string = input_string.replace("n°", " ")

    return output_string