static void Main(string[] args)
{
IK f = new A();
f.methodK();
IJ c = (IJ)f;
c.methodJ();
c.methodK();
IC j = (IC)c;
j.methodC();
j.methodE();
j.methodJ();
j.methodK();
A a = (A)j;
a.methodA();
a.methodB();
a.methodC();
a.methodD();
a.methodE();
a.methodJ();
a.methodK();
}