/* 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
	{
		Set< Integer > integersUnmodifiable = Set.of( 4 , 7 , 12 ) ;
		
		Set< Integer > integers = new HashSet<>() ;
    	integers.addAll( Set.of( 42 , 99 , 177 ) ) ;
    	
    	Set< Integer > integersToBeReturned = Set.copyOf( integers ) ;
    	
    	System.out.println( integersUnmodifiable ) ;
    	System.out.println( integers ) ;
    	System.out.println( integersToBeReturned ) ;
		

	}
}