import java.util.*;
import java.io.*;
import java.text.*;

public class NickyEnMark{
    public static void main(String[] args) throws IOException {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in))) {
            String[] line = reader.readLine().split(" ");
            int n = Integer.parseInt(line[0]);
            line = reader.readLine().split(" ");
            double ans = 0.0;
            for(int i=0;i<n;i++){
                double x = Double.parseDouble(line[i]);
                ans+=x*x*x;
            }
            ans=Math.pow(ans,(1.0/3.0));
            System.out.println(ans);
        }
    }
}