#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;


int main(){
  int D;
  vector<int> A;
  cin >> D;
  rep(i,D+1){
    int a;
    cin >> a;
    A.push_back(a);
  }

  for(int i=D; i>=3; i--){
    A[i-2] += A[i];
    A[i] = 0;
  }

  int mx = -1;
  rep(i,A.size()){
    if(A[i] != 0) mx = i;
  }

  if(mx == -1){
    cout << 0 << endl;
    cout << 0 << endl;
    return 0;
  }
  
  cout << mx << endl;
  rep(i,mx+1){
    if(i!=0) cout << " ";
    cout << A[i];
  }
  cout << endl;
  return 0;
}