import java.util.HashSet;
class Main {
public static void main(String[] args) {
HashSet<Integer> evenNumbers = new HashSet<>();
evenNumbers.add(2);
evenNumbers.add(4);
System.out.println("HashSet1: " + evenNumbers);
HashSet<Integer> numbers = new HashSet<>();
numbers.add(1);
numbers.add(3);
System.out.println("HashSet2: " + numbers);
// Union of two set
numbers.addAll(evenNumbers);
System.out.println("Union is: " + numbers);
}
}