string Manipulation

         string smsIDs = "ID: c857e4916be50e70691f2869beed4d96 To: 447930365407 ID: b75ba5e10f3d8fdf2771955f66d233c0 To: 447956223509";

        char[] delimiterChars = { ' ', ',', '.', ':', '\t' };

        string text = smsIDs;
        string[] words = text.Split(delimiterChars);
        int index = 1;


      foreach (string c in words)
        {
            // if (index == 0)
            {
                if (c.Length > 2)
    ...