#include<stdio.h>

#define NMAX 500007

int a[NMAX];
int n;

int main(){
    freopen("reguli.in", "r", stdin);
    freopen("reguli.out", "w", stdout);
    scanf("%d", &n);
    for(int i = 1; i <= n; ++ i)
        scanf("%d", &a[i]);
    for(int i = n; i >= 0; -- i)
        a[i] -= a[i - 1];
    for(int i = 2; i <= n; ++ i){
        int ok = 0;
        for(int j = i + 1; j <= n; ++ j)
            if(a[j] != a[j - i + 1]){
                ok = 1;
                break;
            }
        if(ok == 0){
            n = i;
            break;
        }
    }
    printf("%d\n", n - 1);
    for(int i = 2; i <= n; ++ i)
        printf("%d\n", a[i]);
    return 0;
}