корекция на код

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;

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

        List<Integer> firstList = Arrays.stream(scanner.nextLine().split(" "))
                .map(Integer::parseInt)
                .collect(Collectors.toList());
        List<Integer> secondList = Arrays.stream(scanner.nextLine().split(" "))
                .map(Integer::parseInt)
                .collect(Collectors.toList());

        List<Integer> resultList = new ArrayList<>();

        int maxLength = Math.max(firstList.size(), secondList.size());

        for (int i = 0; i < maxLength; i++) {
            if (i < firstList.size())
                resultList.add(firstList.get(i));
            if (i < secondList.size())
                resultList.add(secondList.get(i));
        }

        for (Integer num : resultList) {
            System.out.print(num + " ");
        }
    }
}