simple program using constructor in inheritance (Java) (209)

package com.company;
import java.util.Scanner;
class grandfather
{
    public grandfather()
    {
        System.out.println("i am a constructor of grand father class.");
    }
    public grandfather(int a)
    {
        System.out.println("i am overloaded constructor of a grand father class :  " +a);
    }
}
class father extends grandfather{

    public father()
    {

        System.out.println("i ma a constructor of a father class.");
    }
    public father(int b)
    {
        super(0);
        System.out.println("i am overloaded constructor of a  father class: " +b);
    }
}
class son extends father{
    public son()
    {
        super(0);
        System.out.println("i am a constructor of a son class.");
    }
}
public class Program46 {
    public static void main(String[] args) {
        int a=4;
        son obj=new son();

    }
}