#include <iostream>

using namespace std;
struct el_t
{
    double liczba;
    el_t *nast;
};
void pisz(el_t *w)
{
    while (w != 0)
    {
        cout << w -> liczba << endl;
        w = w -> nast;
    }
}
double srednia(el_t *w)
{
    double suma = 0;
    int licz = 0;
    while (w != 0)
    {
        suma += w -> liczba;
        licz++;
        w = w -> nast;
    }
    double sred = suma/licz;
    return sred;
}
void usun(el_t *g)
{
    while (g!= 0)
    {
        el_t *pom = g;
        g = g -> nast;
        delete pom;
    }
}

int main()
{
    el_t *g=0, *a=0;
    double x;
    cin >> x;
    while (x > 0.0)
    {
        if (g == 0)
        {
            g = new el_t;
            g -> liczba = x;
            g -> nast = 0;
            a = g;
        }
        else
        {
            a -> nast = new el_t;
            a = a -> nast;
            a -> liczba = x;
            a -> nast = 0;
        }
        cin >> x;
    }

    cout << endl << endl;

    pisz (g);
    cout << endl << endl;
    double sr = srednia(g);
    cout << sr << endl;
    usun(g);
    return 0;
}