#include <iostream>
#include <iomanip>
using namespace std;
int main() {
	double n,a,sum = 0,ans = 0;
	cin >> n;
	for (int i = 1;i <= n;i++) {
		cin >> a;
		sum += a;
	}
	ans = sum / n;
	cout << fixed << setprecision(2) << ans << endl;
	return 0;
}