#include <bits/stdc++.h>
using namespace std;
 
#define IOS                      \
    ios::sync_with_stdio(false); \
    cin.tie(0);                  \
    cout.tie(0)
#define int long long
//#define double long double

signed main()
{
    IOS;
    int n;cin>>n;
    double sum=0;
    while(n--){
        double a;cin>>a;
        sum+=a*a*a;
    }
    sum=pow(sum,1.0/3.0);
    printf("%.8Lf",sum);
    return 0;
}