C# Shorten String

//Thanks to the guest who posted this - but we can do without the swearing ( )o( )...

private static Random rnd = new Random();
private static string Shorten(string input)
{
    char[] arr = "ABCDEFGHIJKLMNOPQRSTUVWXQY123456789!@#$%^&*()".ToCharArray();
    for (int i = 0; i < 5; i++)
        input += arr[rnd.Next(0, arr.Length)];
    MD5CryptoServiceProvider x = new MD5CryptoServiceProvider();
    byte[] bs = System.Text.Encoding.UTF8.GetBytes(input);
    bs = x.ComputeHash(bs);
    System.Text.StringBuilder s = new System.Text.StringBuilder();
    foreach (byte b in bs)
        s.Append(b.ToString("x2").ToLower());
    return s.ToString().Remove(s.Length / + 5);
}