using System;

​

class Program {

  static void Main(string[] args) {

    int[] cardNumber = new int[16]; // Initialize an integer array to hold the card number

​

    // Generate the first 15 digits of the card number randomly

    Random rand = new Random();

    for (int i = 0; i < 15; i++) {

      cardNumber[i] = rand.Next(10);

    }

​

    // Calculate the last digit of the card number using the Luhn algorithm

    int sum = 0;

    bool alternate = false;

​

    for (int i = cardNumber.Length - 2; i >= 0; i--) {

      int digit = cardNumber[i];

​

      if (alternate) {

        digit *= 2;

​

        if (digit > 9) {

          digit = (digit % 10) + 1;

        }

      }

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      sum += digit;

      alternate = !alternate;

    }

​

    int lastDigit = (10 - (sum % 10)) % 10; // Make sure the last digit is not negative

    cardNumber[15] = lastDigit;

​

    // Print out the card number

    Console.Write("Generated card number: ");

    for (int i = 0; i < cardNumber.Length; i++) {

      Console.Write(cardNumber[i]);

    }

    Console.WriteLine();

  }

}

​