#include<iostream>
#include<math.h>
#include<vector>
#include <array>
#include <algorithm>
#include <queue>
#include <numeric>
#include <map>

using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) //printf(__VA_ARGS__)

typedef pair<int, int> pos;
int pos::*x = &pos::first;
int pos::*y = &pos::second;

int dxy[] = {0, 1, 0, -1, 0};

/*================================*/

int m[4];

signed main()
{
    int D;
    cin >> D;
    D++;
    int n[100010] = {0};
    REP(i,D) cin >> n[i];
    int maxd = D;
    FOR(i,0,D) {
        RFOR(j,0,maxd) {
            if (n[j]) {
                maxd = j;
                break;
            } else if (j == 0) {
                maxd = 0;
                break;
            }
        }
        if (maxd < 3) break;
        n[maxd-2] += n[maxd];
        n[maxd] = 0;
    }
    // 結果
    cout << maxd << endl;
    REP(i,maxd+1) {
        if (i) cout << " ";
        cout << n[i];
    }
    cout << endl;
    
    return 0;
}