import java.util.*;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];

        for(int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        
        Arrays.sort(v);
        double ans = ((double)(v[0] + v[1]) / 2);
        
       
        for(int i = 2; i < N; i++) {
            ans = ((double)(ans + v[i]) / 2);
        }
        
        System.out.println(ans);
        
    }
} 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());
        int[] v = new int[N];

        for(int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        
        Arrays.sort(v);
        double ans = ((double)(v[0] + v[1]) / 2);
        
       
        for(int i = 2; i < N; i++) {
            ans = ((double)(ans + v[i]) / 2);
        }
        
        System.out.println(ans);
        
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];

        for(int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        
        Arrays.sort(v);
        double ans = ((double)(v[0] + v[1]) / 2);
        
       
        for(int i = 2; i < N; i++) {
            ans = ((double)(ans + v[i]) / 2);
        }
        
        System.out.println(ans);
        
    } main {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        int[] v = new int[N];

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

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

        for(int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        
        Arrays.sort(v);
        double ans = ((double)(v[0] + v[1]) / 2);
        
       
        for(int i = 2; i < N; i++) {
            ans = ((double)(ans + v[i]) / 2);
        }
        
        System.out.println(ans);
        
    }
} 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());
        int[] v = new int[N];

        for(int i = 0; i < N; i++) {
            v[i] = Integer.parseInt(sc.next());
        }
        
        Arrays.sort(v);
        double ans = ((double)(v[0] + v[1]) / 2);
        
       
        for(int i = 2; i < N; i++) {
            ans = ((double)(ans + v[i]) / 2);
        }
        
        System.out.println(ans);
        
    }
}