
Answer:
import java.util.*;
public class Main
{
public static void main(String[] args) {
 Â
  Scanner input = new Scanner(System.in);
 Â
  ArrayList<Integer> l1 = new ArrayList<Integer>(5);
  ArrayList<Integer> l2 = new ArrayList<Integer>(5);
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  System.out.println("Enter five integers for list1: ");
  for (int i=0; i<5; i++) {
    int x = input.nextInt();
    l1.add(x);
  }
  System.out.println("Enter five integers for list2: ");
  for (int i=0; i<5; i++) {
    int x = input.nextInt();
    l2.add(x);
  }
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  System.out.println(union(l1, l2));
 Â
}
public static ArrayList<Integer> union(ArrayList<Integer> list, ArrayList<Integer> list2) {
    for (int i:list2)
      list.add(i);
 Â
  return list;
}
}
Explanation:
Create a method called union takes two lists, list and list2
Inside the method:
Initialize a for loop iterates through the list2
Add all the elements in list2 to list
Return the list
Inside the main:
Declare the lists
Ask the user for the numbers and put them in the lists
Call the union method to combine the lists and print the combined list