#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
int n;
double s = 0, a;
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> a;
s += a;
}
double ave = s / n;
cout << fixed << setprecision(4) << ave;
return 0;
}