#include <iostream>
using namespace std;

#define fastcin {\
    cin.tie(0);\
    ios::sync_with_stdio(false);\
}
#define REP(i, a) for(int i = 0; i < a; i++)
#define scan(x) cin >> x
#define print(x) cout << x << "\n"

int main() {
    fastcin;
    int d; scan(d);
    int a[d+1];
    REP(i, d+1) scan(a[i]);

    if (d < 3) {
    } else {
        int b[d-2];
        for (int i = d-4; i >= -1; --i) {
            b[i+1] = a[i+4];
            a[i+2] += b[i+1];
        }
        if (a[2] != 0) d = 2;
        else if (a[1] != 0) d = 1;
        else d = 0;
    }
    print(d);
    REP(i, d+1) cout << a[i] << ' ';

    return 0;
}