public class GrandParent {      

    public void GP() {

        System.Console.WriteLine("I am from GrandParent class");

    }

}

​

public class Parent:GrandParent {   

    public void PT() {

        System.Console.WriteLine("I am from Parent class");

    }

}

​

public class Child:Parent { 

}

​

public class Program

{

    public static void Main()

    {

        Child child = new Child();

        child.PT(); // output: "I am from Parent class"

        child.GP(); // Output: "I am from GrandParent class"

    }

}