#include <cstdio>
#define N 500005
using namespace std;

FILE *f = fopen("reguli.in","r");
FILE *g = fopen("reguli.out","w");

int v[N],s[N],n,pi[N];

int main()
{
    int i,w=0;
    fscanf(f,"%d",&n);
    fscanf(f,"%d",&v[0]);
    for(i=1; i<n; i++)
        {
            fscanf(f,"%d",&v[i]);
            s[i-1] = v[i]-v[i-1];
        }
    n--;
    for(i=1; i<n; i++)
        {
            while(w && s[i] != s[w]) w = pi[w-1];

            if(s[i] == s[w]) w++;

            pi[i] = w;
        }
    fprintf(g,"%d\n",n-pi[n-1]);

    for(i=0; i<n-pi[n-1]; i++)
         fprintf(g,"%d\n",s[i]);
    return 0;
}