import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next()); 
    ArrayList<Double> v= new ArrayList<Double>();
    for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    }
    Collections.sort(v);
    double sum = v.get(0);
    for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    }
    System.out.println(sum);
  }
}
 import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next()); 
    ArrayList<Double> v= new ArrayList<Double>();
    for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    }
    Collections.sort(v);
    double sum = v.get(0);
    for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    }
    System.out.println(sum);
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next()); 
    ArrayList<Double> v= new ArrayList<Double>();
    for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    }
    Collections.sort(v);
    double sum = v.get(0);
    for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    }
    System.out.println(sum);
  } main {
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next()); 
    ArrayList<Double> v= new ArrayList<Double>();
    for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    }
    Collections.sort(v);
    double sum = v.get(0);
    for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    }
    System.out.println(sum);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = Integer.parseInt(sc.next()); N Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc ArrayList<Double> v= new ArrayList<Double>(); v new ArrayList<Double>() for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    } int i=0; int i=0; i 0 i < N i N i++ i++ i {
      v.add(sc.nextDouble());
    } {
      v.add(sc.nextDouble());
    } v.add(sc.nextDouble()) v.add v sc.nextDouble() sc.nextDouble sc Collections.sort(v) Collections.sort Collections v double sum = v.get(0); sum v.get(0) v.get v 0 for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    } int i=1; int i=1; i 1 i < N i N i++ i++ i {
      sum = (sum + v.get(i))/2;
    } {
      sum = (sum + v.get(i))/2;
    } sum = (sum + v.get(i))/2 sum (sum + v.get(i))/2 (sum + v.get(i)) sum v.get(i) v.get v i 2 System.out.println(sum) System.out.println System.out System System.out sum String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next()); 
    ArrayList<Double> v= new ArrayList<Double>();
    for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    }
    Collections.sort(v);
    double sum = v.get(0);
    for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    }
    System.out.println(sum);
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next()); 
    ArrayList<Double> v= new ArrayList<Double>();
    for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    }
    Collections.sort(v);
    double sum = v.get(0);
    for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    }
    System.out.println(sum);
  }
} Main
import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next()); 
    ArrayList<Double> v= new ArrayList<Double>();
    for (int i=0; i < N ;i++) {
      v.add(sc.nextDouble());
    }
    Collections.sort(v);
    double sum = v.get(0);
    for (int i=1; i < N ;i++) {
      sum = (sum + v.get(i))/2;
    }
    System.out.println(sum);
  }
}

