import java.util.ArrayList;
import java.util.Scanner;
import java.util.Collections;
public class Main {
    /**
     * @param args
     */
/**
 * @author shirai_a
 *
 */
    /**
     * @param args
     */
    public static void main(String[] args) {
        ArrayList<Double> intlist = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          }
            sc.close();
        Collections.sort(intlist);
        double tr = intlist.get(0);
        for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        }
        System.out.println(tr);
    }
}
 import java.util.ArrayList; ArrayList java.util import java.util.Scanner; Scanner java.util import java.util.Collections; Collections java.util public class Main {
    /**
     * @param args
     */
/**
 * @author shirai_a
 *
 */
    /**
     * @param args
     */
    public static void main(String[] args) {
        ArrayList<Double> intlist = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          }
            sc.close();
        Collections.sort(intlist);
        double tr = intlist.get(0);
        for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        }
        System.out.println(tr);
    }
} Main /**
     * @param args
     */
    public static void main(String[] args) {
        ArrayList<Double> intlist = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          }
            sc.close();
        Collections.sort(intlist);
        double tr = intlist.get(0);
        for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        }
        System.out.println(tr);
    } main {
        ArrayList<Double> intlist = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          }
            sc.close();
        Collections.sort(intlist);
        double tr = intlist.get(0);
        for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        }
        System.out.println(tr);
    } ArrayList<Double> intlist = new ArrayList<>(); intlist new ArrayList<>() Scanner sc = new Scanner(System.in); sc new Scanner(System.in) sc.nextLine() sc.nextLine sc for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          } String str sc.nextLine().split(" ") sc.nextLine().split sc.nextLine() sc.nextLine sc " " {
            intlist.add(Double.parseDouble(str));
          } {
            intlist.add(Double.parseDouble(str));
          } intlist.add(Double.parseDouble(str)) intlist.add intlist Double.parseDouble(str) Double.parseDouble Double str sc.close() sc.close sc Collections.sort(intlist) Collections.sort Collections intlist double tr = intlist.get(0); tr intlist.get(0) intlist.get intlist 0 for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        } int i = 1; int i = 1; i 1 i < intlist.size() i intlist.size() intlist.size intlist i++ i++ i {
            tr = (tr + intlist.get(i))/2;
        } {
            tr = (tr + intlist.get(i))/2;
        } tr = (tr + intlist.get(i))/2 tr (tr + intlist.get(i))/2 (tr + intlist.get(i)) tr intlist.get(i) intlist.get intlist i 2 System.out.println(tr) System.out.println System.out System System.out tr String[] args args public class Main {
    /**
     * @param args
     */
/**
 * @author shirai_a
 *
 */
    /**
     * @param args
     */
    public static void main(String[] args) {
        ArrayList<Double> intlist = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          }
            sc.close();
        Collections.sort(intlist);
        double tr = intlist.get(0);
        for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        }
        System.out.println(tr);
    }
} public class Main {
    /**
     * @param args
     */
/**
 * @author shirai_a
 *
 */
    /**
     * @param args
     */
    public static void main(String[] args) {
        ArrayList<Double> intlist = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          }
            sc.close();
        Collections.sort(intlist);
        double tr = intlist.get(0);
        for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        }
        System.out.println(tr);
    }
} Main
import java.util.ArrayList;
import java.util.Scanner;
import java.util.Collections;
public class Main {
    /**
     * @param args
     */
/**
 * @author shirai_a
 *
 */
    /**
     * @param args
     */
    public static void main(String[] args) {
        ArrayList<Double> intlist = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        for (String str: sc.nextLine().split(" ")){
            intlist.add(Double.parseDouble(str));
          }
            sc.close();
        Collections.sort(intlist);
        double tr = intlist.get(0);
        for(int i = 1; i < intlist.size(); i++) {
            tr = (tr + intlist.get(i))/2;
        }
        System.out.println(tr);
    }
}

