static void Main(string[] args)
        {
            List<string> list = new List<string>();
            list.Add("\r \n aab bcc");
            list.Add("aab bcc \r  \ndd");
            list.Add("aa\r b b \n cc");
            
            Regex regex = new Regex(@"\s");
            for (int i = 0; i < list.Count;i++ )
            {
                string str = list[i];
                list[i]=regex.Replace(str,"",str.Length);
            }

            foreach(string s in list)
            {
                Console.WriteLine(s);
            }
        }