#include<iostream>
#include<cstdio>
#include<cstring>
#include <cstdlib>  
#include <cmath>   
#include<cctype>
#include<string>
#include<set>
#include<iomanip>
#include <map>
#include<algorithm>
#include <functional>
#include<vector>
#include<climits>
#include<stack>
#include<queue>
#include <deque>
#include <climits>
#include <typeinfo>
#include <utility> 
#define all(x) (x).begin(),(x).end()
#define rep(i,m,n) for(int i = m;i < n;++i)
#define pb push_back
#define fore(i,a) for(auto &i:a)
#define rrep(i,m,n) for(int i = m;i >= n;--i)
#define INF INT_MAX/2
using namespace std;
using ll = long long;
using R = double;
using Data = pair<ll, vector<int>>;
const ll MOD = 1e9 + 7;
const ll inf = 1LL << 50;
struct edge { ll from; ll to; ll cost; };

int main() {
	int d;
	cin >> d;

	vector<int>a(d+1);
	rep(i, 0, d + 1) {
		cin >> a[i];
	}

	int p = 0;
	int q = 0;
	int r = a[0];
	rep(i, 0, d + 1)p += a[i];
	rep(i, 0, d + 1) {
		if (i % 2 == 0)q += a[i];
		else q -= a[i];
	}

	int A = (p + q) / 2 - r;
	int B = (p - q) / 2;
	int C = r;
	if (A == 0) {
		if (B == 0) {
			cout << 0 << endl;
			cout << C << endl;
		}
		else {
			cout << 1 << endl;
			cout << C << " " << B << endl;
		}
	}
	else {
		cout << 2 << endl;
		cout << C << " " << B << " " << A << endl;
	}

	return 0;
}