using System;

using System.Linq;

using Newtonsoft.Json.Linq;

​

public class Program

{

    public static void Main()

    {

        string responseString = "{\"lppdata\":\"wrong pin\"}";

        string responseString1 = "{\"lppdata\":\"wrong pin\"}";

        JObject jo1 = JObject.Parse(responseString);

        JObject jo2 = JObject.Parse(responseString1);

        jo1.Merge(jo2, new JsonMergeSettings

     {

         MergeArrayHandling = MergeArrayHandling.Union

     });

        Console.WriteLine(jo1);

    }

}