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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 verification_digit(numbers):
 """ Returns the verification digit for a given numbre. The verification digit is calculated as follows: * A = sum of all even-positioned numbers * B = A * 3 * C = sum of all odd-positioned numbers * D = B + C * The results is the smallset number N, such that (D + N) % 10 == 0 NOTE: Afip's documentation seems to have odd an even mixed up in the explanation, but all examples follow the above algorithm. :param list(int) numbers):
 The numbers for which the digits is to be calculated. :return: int """

        a = sum(numbers[::2])
        b = a * 3
        c = sum(numbers[1::2])
        d = b + c
        e = d % 10
        if e == 0:
            return e
        return 10 - e