O4. Mixed Up / Lists - More Exercise

package ListsMoreExercise;

import java.util.*;
import java.util.stream.Collectors;

public class O4MixedUpLists {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        List<Integer> a = Arrays.stream(scanner.nextLine().split("\\s+"))
                .map(Integer::parseInt)
                .collect(Collectors.toList());
        List<Integer> b = Arrays.stream(scanner.nextLine().split("\\s+"))
                .map(Integer::parseInt)
                .collect(Collectors.toList());
        int firstIndex = 0;
        int secondIndex = 0;
        List<Integer> combined = new ArrayList<>();
        if (a.size() > b.size()) {
            firstIndex = a.get(a.size() - 1);
            a.remove(a.size() - 1);
            secondIndex = a.get(a.size() - 1);
            a.remove(a.size() - 1);
            Collections.reverse(b);
            for (int i = 0; i < a.size(); i++) {
                combined.add(a.get(i));
                combined.add(b.get(i));
            }

        } else {
            firstIndex = b.get(0);
            b.remove(0);
            secondIndex = b.get(0);
            b.remove(0);
            Collections.reverse(a);
            for (int i = 0; i < b.size(); i++) {
                combined.add(b.get(i));
                combined.add(a.get(i));
            }
        }
        Collections.sort(combined);
        for (Integer integer : combined) {
            if (integer > Math.min(firstIndex, secondIndex) && integer < Math.max(firstIndex, secondIndex)) {
                System.out.print(integer + " ");
            }
        }
    }
}