#include<iostream>
#include<iomanip>
using namespace std;
int a,b;
double c=0;
int main(){
    cin>>a;
    for(int i=0;i<a;i++){
        cin>>b;
        c+=b/(double)a;
    }
    cout<<fixed<<setprecision(2)<<c;
}

开double了怎么精度还是不够