#include <iostream>
#include <vector>
using namespace std;
int main() {
	vector<int> given_pol(4,0);
	given_pol[1] = -1; given_pol[3] = 1;
	int D; cin >> D;
	vector<int> pol(D + 1,0);
	for (int i = 0; i <= D; i++) { cin >> pol[i]; }
	if (D <= 2) {
		cout << D << endl;
		for (int i = 0; i <= D; i++) {
			cout << pol[i] << " ";
		}
		cout << endl;
		return 0;
	}
	for (int i = D; i > 2;i--) {
		if (pol[i] == 0) { continue; }
		pol[i - 2] = pol[i - 2] - given_pol[1] * pol[i];
		/* pol[i] = pol[i] - given_pol[3] * pol[i]; */
		pol[i] = 0;
	}
	if (pol[2] != 0) { 
		cout << 2 << endl;
		cout << pol[0] << " " << pol[1] << " " << pol[2] << endl;
	}
	else if (pol[1] != 0) {
		cout << 1 << endl;
		cout << pol[0] << " " << pol[1] << endl;
	}
	else {
		cout << 0 << endl << 0 << endl;
	}
	return 0;
}