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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 convert_string_to_number(value):
 """ Convert strings to numbers """

    if value is None:
        return 1
    if isinstance(value, int):
        return value
    if value.isdigit():
        return int(value)
    num_list = map(lambda s: NUMBERS[s], re.findall(numbers + '+', value.lower()))
    return sum(num_list)