// C# program to check whether the

// given EMEI number is valid or not.

using System;

​

class Program {

    // Function for finding and

    // returning sum of digits

    // of a number

    static int sumDig(int n)

    {

        int a = 0;

        while (n > 0)

        {

            a = a + n % 10;

            n = n / 10;

        }

        return a;

    }

​

    static Boolean isValidIMEI(long n)

    {

        // Converting the number into

        // String for finding length

        String s = n.ToString();

        int len = s.Length;

​

        if (len != 15)

            return false;

​

        int sum = 0;

        for (int i = len; i >= 1; i--)

        {

            int d = (int)(n % 10);

​

            // Doubling every alternate

            // digit

            if (i % 2 == 0)

                d = 2 * d;

​

            // Finding sum of the digits

            sum += sumDig(d);

            n = n / 10;

        }

​

        return (sum % 10 == 0);

    }

​

    // Driver code

    public static void Main()

    {

​

        // 15 digits cannot be stored in

        // 'int' data type

        long n = 354290371315416L;

​

        if (isValidIMEI(n))

            Console.Write("Valid IMEI Code");

        else

            Console.Write("Invalid IMEI Code");

​

    }

}

​

// This code is contributed by parashar.

​