/* 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 {
		ArrayList<List<Integer>> group = new ArrayList<List<Integer>>();
		group.add(Arrays.asList(1, 2, 3));
		group.add(Arrays.asList(4, 5, 6));
		group.add(Arrays.asList(7, 8, 9));
 
		// Uncomment the below line and you'll see that it won't work
		// group.get(1).add(2342);
 
		for (List<Integer> list : group) {
			for (Integer i : list) {
				System.out.print(i+" ");
			}
			System.out.println();
		}
	}
}

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