#include <bits/stdc++.h>
#define rep(i, n) for(long long i = 0; i < n; i++)
#define ALL(v) (v).begin(), (v).end()
using namespace std;

using lint = long long;

int main() {
    int d;
    cin >> d;
    vector<int> a(d + 1);
    rep(i, d + 1) {
        cin >> a[i];
    }
    for (int i = d; i >= 3; i--) {
        int q = a[i];
        a[i] -= q;
        a[i - 2] += q;
    }
    int right = -1;
    rep(i, d + 1) {
        if (a[i] != 0) {
            right = i;
        }
    }
    if (right == -1) {
        cout << 0 << endl << 0 << endl;
    } else {
        cout << right << endl;
        rep(i, right + 1) {
            cout << a[i] << " ";
        }
        cout << endl;
    }
}