Write a program that reads from a list of credit cards and determines if those cards are valid. Each file provided encodes the credit card numbers are longs. In binary, read each long and process the card.

To determine if a credit card is valid, use the following algorithm.

From the rightmost digit, which is the check digit, and moving left, double the value of every second digit. The check digit is not doubled; the first digit doubled is immediately to the left of the check digit. If the result of this doubling operation is greater than 9 (e. g., 8 × 2 = 16), then add the digits of the result (e. g., 16: 1 + 6 = 7, 18: 1 + 8 = 9) or, alternatively, the same final result can be found by subtracting 9 from that result (e. g., 16: 16 − 9 = 7, 18: 18 − 9 = 9).