import java.util.Scanner;
import java.util.Arrays;
public class Main {
	public static void main(String... args){
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int[] a = new int[N];
      for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      }
      Arrays.sort(a);
      double output = a[0];
      for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      }
      System.out.println(output);
      
    }
} import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util public class Main {
	public static void main(String... args){
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int[] a = new int[N];
      for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      }
      Arrays.sort(a);
      double output = a[0];
      for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      }
      System.out.println(output);
      
    }
} Main public static void main(String... args){
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int[] a = new int[N];
      for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      }
      Arrays.sort(a);
      double output = a[0];
      for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      }
      System.out.println(output);
      
    } main {
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int[] a = new int[N];
      for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      }
      Arrays.sort(a);
      double output = a[0];
      for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      }
      System.out.println(output);
      
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int[] a = new int[N]; a new int[N] N for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
        a[i] = sc.nextInt();
      } {
        a[i] = sc.nextInt();
      } a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc Arrays.sort(a) Arrays.sort Arrays a double output = a[0]; output a[0] a 0 for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      } int i = 1 ; int i = 1 ; i 1 i < N i N i++ i++ i {
      	output = (double)((output + (double) a[i]) / 2);
      } {
      	output = (double)((output + (double) a[i]) / 2);
      } output = (double)((output + (double) a[i]) / 2) output (double)((output + (double) a[i]) / 2) (output + (double) a[i]) output (double) a[i] a i 2 System.out.println(output) System.out.println System.out System System.out output String... args args public class Main {
	public static void main(String... args){
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int[] a = new int[N];
      for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      }
      Arrays.sort(a);
      double output = a[0];
      for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      }
      System.out.println(output);
      
    }
} public class Main {
	public static void main(String... args){
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int[] a = new int[N];
      for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      }
      Arrays.sort(a);
      double output = a[0];
      for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      }
      System.out.println(output);
      
    }
} Main
import java.util.Scanner;
import java.util.Arrays;
public class Main {
	public static void main(String... args){
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int[] a = new int[N];
      for(int i = 0; i < N; i++) {
        a[i] = sc.nextInt();
      }
      Arrays.sort(a);
      double output = a[0];
      for(int i = 1 ; i < N ; i++) {
      	output = (double)((output + (double) a[i]) / 2);
      }
      System.out.println(output);
      
    }
}