#include <fstream>
using namespace std;

ifstream is("reguli.in");
ofstream os("reguli.out");

long long N, K, x, y, aux;
long long D[500001];
int PI[500001];

int main()
{
    is >> N;
    for ( int i = 1; i <= N; ++i )
    {
        if ( i == 1 )
            is >> x >> y;
        else
        {
            x = y;
            is >> y;
        }
        D[i] = y-x;
    }

    K = 0;
    for ( int i = 2; i <= N-1; ++i )
    {
        while ( K > 0 && D[K+1] != D[i] )
            K = PI[K];

        if ( D[K+1] == D[i] )
            ++K;

        PI[i] = K;
    }

    os << (N-1) - PI[N-1] << '\n';
    for ( int i = 1; i <= ((N-1)-PI[N-1]); ++i )
        os << D[i] << '\n';


    is.close();
    os.close();
}