#include <iostream>
#include <vector>

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);

	int d;
	std::vector<int> a;
	int result_rank = 0;

	std::cin >> d;
	for (int i = 0; i <= d; ++i) {
		int tmp;
		std::cin >> tmp;
		a.push_back(tmp);
	}
	if (d <= 2) {
		result_rank = d;
		std::cout << d << "\n";
	}
	else {
		for (auto rit = a.rbegin(); rit != a.rend() - 3; ++rit) {
			*(rit + 2) += (*rit);
			*rit = 0;
		}
		for (int i = 2; i > 0; --i) {
			if (a[i] != 0) {
				result_rank = i;
				std::cout << i << "\n";
				break;
			}
		}
		if (result_rank == 0) {
			std::cout << 0 << "\n";
		}
	}
	for (int i = 0; i <= result_rank; ++i) {
		std::cout << a[i] << " ";
	}
	std::cout << "\n";

	return 0;
}