#include <bits/stdc++.h>
using namespace std;

int main() {
	double s,z,zong;
	cin >> s;
	for(int i=1;i<=s;i++){
		cin >> z;
		zong =zong+z;

	  
	  
}
     cout << setprecision(2) << fixed << zong/s << endl;



	return 0;
}