#include<stdio.h>

#define NMAX 500007

int a[NMAX], b[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", &b[i]);
    for(int i = 1; i <= n; ++ i)
        a[i] = b[i + 1] - b[i];
    -- n;
    for(int i = 1; i <= n; ++ i){
        int ok = 0;
        for(int j = i + 1; j <= n; ++ j)
            if(a[j] != a[j - i]){
                ok = 1;
                break;
            }
        if(ok == 0){
            n = i;
            break;
        }
    }
    printf("%d\n", n);
    for(int i = 1; i <= n; ++ i)
        printf("%d\n", a[i]);
    return 0;
}