/// https://www.infoarena.ro/automate-finite-si-kmp
#include <fstream>
#include <cstring>

using namespace std;

const int NMAX = 5e5 + 1;

ifstream fin("reguli.in");
ofstream fout("reguli.out");

int n, a[NMAX], pi[NMAX];

void calcPrefix()
{
    int x = 0;
    pi[1] = 0;
    for(int i = 1; i < n; ++i)
    {
        while(x > 0 && a[x] != a[i])
            x = pi[x - 1];
        if(a[x] == a[i])
            ++x;
        pi[i] = x;
    }
}

void citire()
{
    fin >> n >> a[0];
    for(int i = 1; i <= n; ++i)
    {
        fin >> a[i];
        a[i - 1] = a[i] - a[i - 1];
    }
    --n;
}

void solutie()
{
    calcPrefix();
    fout << n - pi[n - 1] << "\n";
    for(int i = 0; i < n - pi[n - 1]; ++i) fout << a[i] << "\n";
}

int main()
{
    citire();
    solutie();
    return 0;
}