include <stdio.h>
#include <math.h>
#include <iostream>
using namespace std;
int main()
{
	double n,sum = 0,x;
	cin >>n;
	for(int i = 0; i < n ; i++)
	{
		cin >> x;
		sum += x;
	}
	printf("%.2lf\n",sum/n);
}