#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>
#include <cstdio>
#include <cmath>

using namespace std;

int main() {

	int D, A[10005] = {};
	int td, b[10005] = {};
	
	cin >> D;
	for (int i = 0; i < D + 1; i++) {
		cin >> A[i];
		b[i] = A[i];
	}

	for (int i = D; 3 <= i; i--) {
		b[i - 2] += b[i];
		b[i] = 0;
	}

	td = 0;
	for (int i = D; 0 <= i; i--) {
		if (b[i] != 0) {
			td = i;
			break;
		}
	}

	cout << td << endl;
	for (int i = 0; i < td + 1; i++) {
		cout << b[i] << " ";
	}
	cout << endl;

	return 0;
}