#include <algorithm> #include <climits> #include <cmath> #include <cstdio> #include <cstdlib> #include <ctime> #include <iostream> #include <sstream> #include <functional> #include <map> #include <string> #include <cstring> #include <vector> #include <queue> #include <stack> #include <deque> #include <set> #include <list> #include <numeric> using namespace std; const double PI = 3.14159265358979323846; const double EPS = 1e-12; const int INF = 1<<25; typedef pair<int,int> P; typedef long long ll; typedef unsigned long long ull; #define rep(i,n) for(int (i)=0;(i)<(ll)(n);++(i)) #define repd(i,n,d) for(ll (i)=0;(i)<(ll)(n);(i)+=(d)) #define all(v) (v).begin(), (v).end() #define pb(x) push_back(x) #define mp(x,y) make_pair((x),(y)) #define mset(m,v) memset((m),(v),sizeof(m)) #define chmin(X,Y) ((X)>(Y)?X=(Y),true:false) #define chmax(X,Y) ((X)<(Y)?X=(Y),true:false) #define fst first #define snd second #define UNIQUE(x) (x).erase(unique(all(x)),(x).end()) template<class T> ostream &operator<<(ostream &os, const vector<T> &v){int n=v.size();rep(i,n)os<<v[i]<<(i==n-1?"":" ");return os;} #define N 100010 ll n; ll b[N], a[N+1]; int main(){ cin>>n; rep(i, n) cin>>b[i]; a[0] = 0; rep(i, n) a[i+1] = (-a[i]+b[i])*(i%2?-1:1); ll lb = 1, ub = 1e18; rep(i, n+1){ int t = i%4; if(t==1||t==2){ chmax(lb, -1e18+a[i]); chmin(ub, -1+a[i]); } else { chmax(lb, 1-a[i]); chmin(ub, 1e18-a[i]); } } if(lb>ub) cout<<-1<<endl; else { cout<<n+1<<endl; rep(i, n+1) cout<<a[i]+lb*((i&1)!=((i>>1)&1)?-1:1)<<endl; } return 0; }