#include <bits/stdc++.h>
using namespace std;
ifstream fin("reguli.in");
ofstream fout("reguli.out");
const int lim =500001;
int n, m, lps[lim], v[1005], t,w=1e9;
int a[lim],b[lim];
void precalc()
{
    int k = 0;
    for (int i = 2; i <=t-1 ; ++i)
    {
        while (k && a[k] != a[i - 1]) k = lps[k];
        if (a[k] == a[i - 1]) k++;
        lps[i] = k;
        if(lps[i])
        if(!(i%(i-lps[i])))
          w=min(i,w);
    }
}
int main()
{fin>>t;
for(int i=0;i<=t-1;++i)
  fin>>b[i];
  for(int i=0;i<=t;++i)
 a[i]=b[i+1]-b[i];
    precalc();
    if(!lps[w] && !(w%(w-lps[w])))
      w=lps[w];
    w/=2;
    fout<<w<<'\n';
    for(int j=0;j<=w-1;++j)
      fout<<a[j]<<'\n';

    return 0;
}