import java.util.Scanner;
import java.util.Collections;
import java.util.List;
import java.util.ArrayList;
public class Main {
  public static void main(String... args) {
    Scanner scan = new Scanner(System.in);
    int count = scan.nextInt();
    List<Integer> list = new ArrayList<>();
    while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    }
    Collections.sort(list);
    double x = 0;
    for (int num : list) {
      x = x==0?num:(num+x)/2;
    }
    System.out.println(x);
  }
} import java.util.Scanner; Scanner java.util import java.util.Collections; Collections java.util import java.util.List; List java.util import java.util.ArrayList; ArrayList java.util public class Main {
  public static void main(String... args) {
    Scanner scan = new Scanner(System.in);
    int count = scan.nextInt();
    List<Integer> list = new ArrayList<>();
    while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    }
    Collections.sort(list);
    double x = 0;
    for (int num : list) {
      x = x==0?num:(num+x)/2;
    }
    System.out.println(x);
  }
} Main public static void main(String... args) {
    Scanner scan = new Scanner(System.in);
    int count = scan.nextInt();
    List<Integer> list = new ArrayList<>();
    while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    }
    Collections.sort(list);
    double x = 0;
    for (int num : list) {
      x = x==0?num:(num+x)/2;
    }
    System.out.println(x);
  } main {
    Scanner scan = new Scanner(System.in);
    int count = scan.nextInt();
    List<Integer> list = new ArrayList<>();
    while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    }
    Collections.sort(list);
    double x = 0;
    for (int num : list) {
      x = x==0?num:(num+x)/2;
    }
    System.out.println(x);
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int count = scan.nextInt(); count scan.nextInt() scan.nextInt scan List<Integer> list = new ArrayList<>(); list new ArrayList<>() while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    } scan.hasNextInt() scan.hasNextInt scan {
      list.add(scan.nextInt());
    } list.add(scan.nextInt()) list.add list scan.nextInt() scan.nextInt scan Collections.sort(list) Collections.sort Collections list double x = 0; x 0 for (int num : list) {
      x = x==0?num:(num+x)/2;
    } int num list {
      x = x==0?num:(num+x)/2;
    } {
      x = x==0?num:(num+x)/2;
    } x = x==0?num:(num+x)/2 x x==0?num:(num+x)/2 x==0 x 0 num (num+x)/2 (num+x) num x 2 System.out.println(x) System.out.println System.out System System.out x String... args args public class Main {
  public static void main(String... args) {
    Scanner scan = new Scanner(System.in);
    int count = scan.nextInt();
    List<Integer> list = new ArrayList<>();
    while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    }
    Collections.sort(list);
    double x = 0;
    for (int num : list) {
      x = x==0?num:(num+x)/2;
    }
    System.out.println(x);
  }
} public class Main {
  public static void main(String... args) {
    Scanner scan = new Scanner(System.in);
    int count = scan.nextInt();
    List<Integer> list = new ArrayList<>();
    while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    }
    Collections.sort(list);
    double x = 0;
    for (int num : list) {
      x = x==0?num:(num+x)/2;
    }
    System.out.println(x);
  }
} Main
import java.util.Scanner;
import java.util.Collections;
import java.util.List;
import java.util.ArrayList;
public class Main {
  public static void main(String... args) {
    Scanner scan = new Scanner(System.in);
    int count = scan.nextInt();
    List<Integer> list = new ArrayList<>();
    while (scan.hasNextInt()) {
      list.add(scan.nextInt());
    }
    Collections.sort(list);
    double x = 0;
    for (int num : list) {
      x = x==0?num:(num+x)/2;
    }
    System.out.println(x);
  }
}