Thread: Where should I toggle the breakpoints ?

I'd like to understand how this program runs but I dont know where to toggle the breakpoints .

abstract class A
{
    abstract void firstMethod();
 
    void secondMethod()
    {
        System.out.println("SECOND");
 
        firstMethod();
    }
}
 
abstract class B extends A
{
    @Override
    void firstMethod()
    {
        System.out.println("FIRST");
 
        thirdMethod();
    }
 
    abstract void thirdMethod();
}
 
class C extends B
{
    @Override
    void thirdMethod()
    {
        System.out.println("THIRD");
    }
}
 
public class MainClass1
{
    public static void main(String[] args)
    {
        C c = new C();
 
        c.firstMethod();
 
        c.secondMethod();
 
        c.thirdMethod();
    }
}

Put just one breakpoint on "c.firstMethod();" near the bottom and then use Step Into exclusively. Each statement it stops at is another place where you could put a breakpoint if you wanted.