#include<algorithm>

#include<cmath>

#include<cstdio>

#include<iostream>

using namespace std;

int main(){

int n;

cin>>n;

double age,sum=0;

for(int i=1;i<=n;i++){

cin>>age;

sum+=age;

}

printf("%.2lf",sum/(n*1.0));

return 0;

}