package no040;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int d = sc.nextInt();
		int[] a = new int[d+1];
		for(int i=0;i<=d;i++) {
			a[i] = sc.nextInt();
		}
		for(int i=0;i<=d-3;i++) {
			a[d-i-2] += a[d-i];
			a[d-i] = 0;
		}
		int d_ = 0;
		for(int i=0;i<=d;i++) {
			if (a[i] != 0) {
				d_ = i;
			}
		}
		System.out.println(d_);
		StringBuilder sb = new StringBuilder();
		for(int i=0;i<=d_;i++) {
			if (i > 0) {
				sb.append(' ');
			}
			sb.append(a[i]);
		}
		System.out.println(sb.toString());
	}

}