interface customer
{
    int a=20;
    void purchase();
}
class Owner implements customer
{
    @Override
    public void purchase()
    {
        System.out.println("customer bought "+a + "kg");
    }
    
    
}
class A
{
    public static void main(String[] args)
    {
        
        System.out.println(customer.a+"kg");/* it can be call without making an obj that is why its static*/
    }
}