#include <iostream>
#include <iomanip>

using namespace std;

int main()
{
    int n;
    int sum = 0;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        int k;
        cin >> k;
        sum += k;
    }
    setprecision(6);
    cout << fixed<< sum / (double) n << endl;
    return 0;
}