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