#include <iostream>

#include<iomanip>

using namespace std;

int main()

{

int n;
double a,sum;

sum = 0;

cin >> n;

for (int i = 1; i <= n; i++)

{

cin >> a;

sum += a;

}

double ave = 1.0*sum / n;

cout << fixed << setprecision(4) << ave << endl;

}