#include<stdio.h>
#include<string.h>
using namespace std;

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

int n,x,y,i,j,k,v[500005],um[500005];

int main() {

    fscanf(f,"%d%d",&n,&x);
    for(i=2;i<=n;i++) {
        fscanf(f,"%d",&y);
        v[i-2]=y-x;
        x=y;
    }
    k=0; um[1]=0;
    for(i=2;i<=n-1;i++) {
        while(k>0&&v[k]!=v[i-1]) k=um[k];
        if(v[k]==v[i-1]) k++;
        um[i]=k;
    }
    for(i=n-1;i>=1;i--) {
        if(um[i]!=0&&(i%(i-um[i])==0)) {
            fprintf(g,"%d\n",i-um[i]);
            for(j=0;j<i-um[i];j++) fprintf(g,"%d\n",v[j]);
            break;
        }
     }

     fclose(f); fclose(g);

     return 0;
}