import java.util.Arrays;
import java.util.Scanner;
class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    double[] indegrients = new double[n];
    for(int i = 0; i < n; i++){
      indegrients[i] = Integer.parseInt(sc.next());
    }
    Arrays.sort(indegrients);
    for(int i = 0; i < n - 1; i++){
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    }
    System.out.println(indegrients[n - 1]);
  }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    double[] indegrients = new double[n];
    for(int i = 0; i < n; i++){
      indegrients[i] = Integer.parseInt(sc.next());
    }
    Arrays.sort(indegrients);
    for(int i = 0; i < n - 1; i++){
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    }
    System.out.println(indegrients[n - 1]);
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    double[] indegrients = new double[n];
    for(int i = 0; i < n; i++){
      indegrients[i] = Integer.parseInt(sc.next());
    }
    Arrays.sort(indegrients);
    for(int i = 0; i < n - 1; i++){
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    }
    System.out.println(indegrients[n - 1]);
  } main {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    double[] indegrients = new double[n];
    for(int i = 0; i < n; i++){
      indegrients[i] = Integer.parseInt(sc.next());
    }
    Arrays.sort(indegrients);
    for(int i = 0; i < n - 1; i++){
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    }
    System.out.println(indegrients[n - 1]);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc double[] indegrients = new double[n]; indegrients new double[n] n for(int i = 0; i < n; i++){
      indegrients[i] = Integer.parseInt(sc.next());
    } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
      indegrients[i] = Integer.parseInt(sc.next());
    } {
      indegrients[i] = Integer.parseInt(sc.next());
    } indegrients[i] = Integer.parseInt(sc.next()) indegrients[i] indegrients i Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc Arrays.sort(indegrients) Arrays.sort Arrays indegrients for(int i = 0; i < n - 1; i++){
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    } int i = 0; int i = 0; i 0 i < n - 1 i n - 1 n 1 i++ i++ i {
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    } {
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    } indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0 indegrients[i + 1] indegrients i + 1 i 1 (indegrients[i] + indegrients[i + 1]) / 2.0 (indegrients[i] + indegrients[i + 1]) indegrients[i] indegrients i indegrients[i + 1] indegrients i + 1 i 1 2.0 System.out.println(indegrients[n - 1]) System.out.println System.out System System.out indegrients[n - 1] indegrients n - 1 n 1 String[] args args
import java.util.Arrays;
import java.util.Scanner;
class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    double[] indegrients = new double[n];
    for(int i = 0; i < n; i++){
      indegrients[i] = Integer.parseInt(sc.next());
    }
    Arrays.sort(indegrients);
    for(int i = 0; i < n - 1; i++){
      indegrients[i + 1] = (indegrients[i] + indegrients[i + 1]) / 2.0;
    }
    System.out.println(indegrients[n - 1]);
  }
}