#include <bits/stdc++.h>

#define MAXN 500005

int LPS[MAXN];

void ComputeLPS(int N, int String[]) {
    for (int i=2, Len=0; i<=N; ++i) {
        while (Len && String[i] != String[Len+1])
            Len = LPS[Len];
        if (String[i] == String[Len+1]) ++ Len;

        LPS[i] = Len;
    }
}

std::ifstream In("reguli.in");
std::ofstream Out("reguli.out");

int N;
int V[MAXN];

void Citire() {
    In >> N;
    int X, Y; In >> X;
    for (int i=1; i<N; ++i)
        In >> Y,
        V[i] = Y-X,
        X = Y;
}

void Rezolvare() {
    --N;
    ComputeLPS(N, V);

    int Ans = N - LPS[N];
    Out << Ans << '\n';
    for (int i=1; i<=Ans; ++i)
        Out << V[i] << '\n' ;
}

int main()
{
    Citire();
    Rezolvare();

    return 0;
}