using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string input = "hjblkajb    vASDV©∆˙∆˚˙√∆ç√˙DFBASD≈˙®ß$^@%&^*^&*#$%@\"\"\"ascbadfbas";

        string output = MakeJsonSafe(input);

        string expected = "hjblkajb \\tvASDV\\u00A9\\u2206\\u02D9\\u2206\\u02DA\\u02D9\\u221A\\u2206\\u00E7\\u221A\\u02D9DFBASD\\u2248\\u02D9\\u00AE\\u00DF$^@%&^*^&*#$%@\\\"\\\"\\\"ascbadfbas";

        Console.WriteLine(input);

        Console.WriteLine(output);

        Console.WriteLine(expected);

    }

    public static string MakeJsonSafe(String s)

    {

        var jsonEscaped = s.Replace("\\", "\\\\")

                           .Replace("\"", "\\\"")

                           .Replace("\b", "\\b")

                           .Replace("\f", "\\f")

                           .Replace("\n", "\\n")

                           .Replace("\r", "\\r")

                           .Replace("\t", "\\t");

        var nonAsciiEscaped = jsonEscaped.Select((c) => c >= 127 ? "\\u" + ((int)c).ToString("X").PadLeft(4, '0') : c.ToString());

        return string.Join("", nonAsciiEscaped);

    }

}