import java.util.*;
import java.lang.*;

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

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] v = new int[n];
        for(int i = 0;i<n;i++){
            v[i] = sc.nextInt();
        }
        Arrays.sort(v);
        double kari = v[0];
        for(int i = 1;i<n;i++){
            kari = (kari + (double)(v[i])) / 2;
        }
        System.out.println(kari);
        sc.close();
    }
}