package PredvaritelnoAdvanced.Tesove;

import java.util.*;

public class Socks {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        ArrayDeque<Integer> stackRight = new ArrayDeque<>();
        Arrays.stream(scanner.nextLine().split("\\s+")).mapToInt(Integer::parseInt).forEach(stackRight::push);
        ArrayDeque<Integer> dequeLeft = new ArrayDeque<>();
        Arrays.stream(scanner.nextLine().split("\\s+")).mapToInt(Integer::parseInt).forEach(dequeLeft::offer);
        List<Integer> pairs = new ArrayList<>();
        while (stackRight.size() > 0 && dequeLeft.size() > 0) {
            int right = stackRight.peek();
            int left = dequeLeft.peek();
            if (right == left) {
                stackRight.pop();
                dequeLeft.poll();
                stackRight.push(right + 1);
            } else if (right < left) {
                stackRight.pop();
            } else {
                pairs.add(right + left);
                stackRight.pop();
                dequeLeft.poll();
            }
        }
        System.out.println(pairs.stream().max(Integer::compareTo).get());
        System.out.println(Arrays.toString(pairs.toArray()).replaceAll("[\\[\\],]", ""));
    }
}