import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	class Abc {}

	public static void main (String[] args) throws java.lang.Exception
	{
		List<Abc> a = new ArrayList<>();
		Object b = a;
		List<Ideone> c = (List<Ideone>)b;
		
		c.add(new Ideone());
		
		// System.out.println(a.get(0).getClass().getName());
	}
}