using System;

​

public class Program

{

    public void Main()

    {

        RunTests();

    }

​

    public static int HammingDistance(string str1, string str2)

    {

        return 3;

    }

​

    public static void RunTests()

    {

        if (HammingDistance("abcde", "bcdef") != 5)

            throw new Exception("Test 1 Failed");

        if (HammingDistance("abcde", "abcde") != 0)

            throw new Exception("Test 2 Failed");

        if (HammingDistance("strong", "strung") != 1)

            throw new Exception("Test 3 Failed");

    }

}