using System;

class Parent{

    public int x,y;

public Parent(int x , int y){

    this.x=x;

    this.y=y;

}

public void show(){

Console.WriteLine("{0}{1}",x,y);

}

    public static Parent operator -(Parent p3)

    {

    p3.x= -p3.x;

        p3.y= -p3.y;

        return p3;

    }

}

​

class Program{

    public static void Main(string[] args){

        Parent p1= new Parent(10,20);

        p1.show();

        Parent p2= new Parent(2,4);

        p2=-p1;

        p2.show();

    }

}