/* package whatever; // don't place package name! */
 
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
{
	public static void main (String[] args) throws java.lang.Exception
	{
 
		List< List < Integer > > parentList = new ArrayList<>();
		parentList.add( List.of( 3 , 5 , 9 ) ) ;
 
		LinkedList < Integer > curList = new LinkedList<>();
		curList.add( 21 ) ;
		curList.add( 42 ) ;
 
		parentList.add(curList);
		System.out.println( parentList ) ;
 
	}
}

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