using System;

public class A

{

    public int x;

    protected int y;

    private int z;

}

public class B:A

{

    private int d;

    protected int e;

    public void Foo()

    {

        x=2;

        y=2;

        d=2;

        e=2;

    }

}

public class Program

{

    public static void Main()

    {

        B b=new B();

        b.x=1;

    //It's OK to define public z in class B, but there will be warnings if I define public x and y. 

    //The warning says 'B.x hides inherited member A.x'. 

    //As we know a derived class can access both public and protected members of the base class.

    //If you define it again, it is just like that you want hide their original values and give them new lives.

    //As for z, it is a private integer and it cannot be accessed in class B, so it's fine to define z again.

    }

}