# include <bits/stdc++.h>
//ccccccccccccccccccccccccccccccccccccccccc
//+++++++++++++++++++++++++++++++++++++++++
//+++++++++++++++++++++++++++++++++++++++++
using namespace std;
double n,k,sum;
int main(){
	cin>>n;
	for(int i = 1;i<=n;i++){
		cin>>k;
		sum+=k;
	}
	printf("%.2lf\n",sum/n);
	return 0;
}