How to get MD5 key?

public string CalculateMD5Hash(string input)
{
// step 1, calculate MD5 hash from input     MD5 md5 = System.Security.Cryptography.MD5.Create();
    byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);     byte[] hash = md5.ComputeHash(inputBytes);// step 2, convert byte array to hex string
    StringBuilder sb = new StringBuilder();     for (int i = 0; i < hash.Length; i++)     {         sb.Append(hash[i].ToString("X2"));     }     return sb.ToString();
}

Call The Function.
string hash = CalculateMD5Hash("abcdefghijklmnopqrstuvwxyz");

You will get output like this..

C3FCD3D76192E4007DFB496CCA67E13B