#include <iostream>
#include <fstream>
#include <string>
using namespace std;
//---------------------------------------------
const string CDfv = "Duomenys.txt";
const int CMax = 500;
//---------------------------------------------
void Skaityti(double A[], int & n);
double Vidurkis(double A[], int n);
//---------------------------------------------
int main()
{
    double A[CMax];
    int n;
    Skaityti(A, n);
    cout << Vidurkis(A, n) << endl;
    return 0;
}
//---------------------------------------------
void Skaityti(double A[], int & n)
{
    double ugis;
    ifstream fd(CDfv);
    fd >> n;
    for(int i = 0; i < n; i++)
    {
        fd >> ugis;
    if(ugis < 0)
        A[i] = ugis * (-1);
    else
        A[i] = ugis;
    }
}
//---------------------------------------------
double Vidurkis(double A[], int n)
{
    double suma = 0;
    for(int i = 0; i < n; i++)
        suma = suma + A[i];
    return suma / n;
}