// No.40 多項式の割り算
#include <iostream>
#include <vector>
using namespace std;

int main() {
    int D;
    cin >> D;
    vector<int> a(D + 1);
    for (int i = 0; i <= D; ++i) cin >> a[i];
    for (int i = D; i >= 3; --i) {
        a[i - 2] += a[i];
        a[i] = 0;
    }
    if (a[2] == 0 && a[1] == 0) {
        cout << 0 << endl;
        cout << a[0] << endl;
    } else if (a[2] == 0) {
        cout << 1 << endl;
        cout << a[0] << " " << a[1] << endl;
    } else {
        cout << 2 << endl;
        cout << a[0] << " " << a[1] << " " << a[2] << endl;
    }
}