#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

const long long MAX = 5100000;
const long long INF = 1LL << 60;
const long long mod = 1000000007LL;
//const long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;



int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/

	ll n; scanf("%lld", &n);
	vector<ll> b(n); for (ll i = 0; i < n; i++) scanf("%lld", &b[i]);
	vector<ll> a(n + 1);
	a[0] = 1;
	for (ll i = 0; i < n; i++) {
		if (i % 2 == 0) {
			a[i + 1] = b[i] - a[i];
		}
		else {
			a[i + 1] = a[i] - b[i];
		}
	}

	ll mn = INF;
	for (ll i = 0; i <= n; i++) {
		if (i % 4 == 0 || i % 4 == 3) {
			chmin(mn, a[i]);
		}
	}
	if (mn < 0) {
		for (ll i = 0; i <= n; i++) {
			if (i % 4 == 0 || i % 4 == 3) {
				a[i] -= mn - 1;
			}
			else {
				a[i] += mn - 1;
			}
		}
	}
	for (ll i = 0; i <= n; i++) {
		if (a[i] <= 0 || a[i] > 1000000000000000000LL) {
			puts("-1");
			return 0;
		}
	}
	printf("%lld\n", n + 1);
	for (ll i = 0; i <= n; i++) {
		printf("%lld\n", a[i]);
	}
	return 0;
}