using System;

using System.Text.Json;

using System.Text.Json.Nodes;

public class Program

{

    public static void Main()

    {

        // Your JSON string representing the derived class

        string jsonString = "{\"name\":\"New York\",\"population\":10000000,\"otherProperty\":\"Some Value\"}";

​

        var jsonObject = JsonNode.Parse(jsonString).AsObject();

        // Modify the "name" property

        jsonObject["name"] = "Updated City Name";

​

        // Serialize the JObject back to a JSON string

        string modifiedJsonString = jsonObject.ToString();

​

        Console.WriteLine(modifiedJsonString);

    }

}