#include<bits/stdc++.h>
using namespace std;
double a,b;
int sum(double n) {
	int s;
	for(; n>0; n--) {
		cin>>s;
		a+=s;
	}
	return a;
}
int main() {
	double n;
	cin>>n;
	b=sum(n)/n;
	printf("%.2lf",b);
	return 0;
}