import java.util.*;
public class Main{

 public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        }
        Arrays.sort(list);

        for(int i=0;i<n;i++){
        }
        double result = (double)list[0];
        for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        }
        System.out.println(result);
    }

} import java.util.*; util.* java public class Main{

 public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        }
        Arrays.sort(list);

        for(int i=0;i<n;i++){
        }
        double result = (double)list[0];
        for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        }
        System.out.println(result);
    }

} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        }
        Arrays.sort(list);

        for(int i=0;i<n;i++){
        }
        double result = (double)list[0];
        for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        }
        System.out.println(result);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        }
        Arrays.sort(list);

        for(int i=0;i<n;i++){
        }
        double result = (double)list[0];
        for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        }
        System.out.println(result);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] list = new int[n]; list new int[n] n for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        } int i=0; int i=0; i 0 i<n i n i++ i++ i {
            list[i] = sc.nextInt();
        } {
            list[i] = sc.nextInt();
        } list[i] = sc.nextInt() list[i] list i sc.nextInt() sc.nextInt sc Arrays.sort(list) Arrays.sort Arrays list for(int i=0;i<n;i++){
        } int i=0; int i=0; i 0 i<n i n i++ i++ i {
        } {
        } double result = (double)list[0]; result (double)list[0] list 0 for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        } int j=1; int j=1; j 1 j<n j n j++ j++ j {
            result = (double)((result + list[j]) /2);
        } {
            result = (double)((result + list[j]) /2);
        } result = (double)((result + list[j]) /2) result (double)((result + list[j]) /2) (result + list[j]) result list[j] list j 2 System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main{

 public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        }
        Arrays.sort(list);

        for(int i=0;i<n;i++){
        }
        double result = (double)list[0];
        for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        }
        System.out.println(result);
    }

} public class Main{

 public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        }
        Arrays.sort(list);

        for(int i=0;i<n;i++){
        }
        double result = (double)list[0];
        for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        }
        System.out.println(result);
    }

} Main
import java.util.*;
public class Main{

 public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] list = new int[n];
        for(int i=0;i<n;i++){
            list[i] = sc.nextInt();
        }
        Arrays.sort(list);

        for(int i=0;i<n;i++){
        }
        double result = (double)list[0];
        for(int j=1;j<n;j++){
            result = (double)((result + list[j]) /2);
        }
        System.out.println(result);
    }

}