import java.util.Arrays;
import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] items = new int[N];

        for (int i = 0; i < N; i ++) {
        	items[i] = sc.nextInt();
        }

        sc.close();

        Arrays.sort(items);

        double sum = items[0];
        int item;
        for (int i = 0 ; i < N-1 ; i++ ) {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        }

        System.out.println(sum);



    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] items = new int[N];

        for (int i = 0; i < N; i ++) {
        	items[i] = sc.nextInt();
        }

        sc.close();

        Arrays.sort(items);

        double sum = items[0];
        int item;
        for (int i = 0 ; i < N-1 ; i++ ) {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        }

        System.out.println(sum);



    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] items = new int[N];

        for (int i = 0; i < N; i ++) {
        	items[i] = sc.nextInt();
        }

        sc.close();

        Arrays.sort(items);

        double sum = items[0];
        int item;
        for (int i = 0 ; i < N-1 ; i++ ) {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        }

        System.out.println(sum);



    } main {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] items = new int[N];

        for (int i = 0; i < N; i ++) {
        	items[i] = sc.nextInt();
        }

        sc.close();

        Arrays.sort(items);

        double sum = items[0];
        int item;
        for (int i = 0 ; i < N-1 ; i++ ) {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        }

        System.out.println(sum);



    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int[] items = new int[N]; items new int[N] N for (int i = 0; i < N; i ++) {
        	items[i] = sc.nextInt();
        } int i = 0; int i = 0; i 0 i < N i N i ++ i ++ i {
        	items[i] = sc.nextInt();
        } {
        	items[i] = sc.nextInt();
        } items[i] = sc.nextInt() items[i] items i sc.nextInt() sc.nextInt sc sc.close() sc.close sc Arrays.sort(items) Arrays.sort Arrays items double sum = items[0]; sum items[0] items 0 int item; item for (int i = 0 ; i < N-1 ; i++ ) {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        } int i = 0 ; int i = 0 ; i 0 i < N-1 i N-1 N 1 i++ i++ i {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        } {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        } item = items[i+1] item items[i+1] items i+1 i 1 sum = (sum + item) / 2 sum (sum + item) / 2 (sum + item) sum item 2 System.out.println(sum) System.out.println System.out System System.out sum String[] args args
import java.util.Arrays;
import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] items = new int[N];

        for (int i = 0; i < N; i ++) {
        	items[i] = sc.nextInt();
        }

        sc.close();

        Arrays.sort(items);

        double sum = items[0];
        int item;
        for (int i = 0 ; i < N-1 ; i++ ) {
        	item = items[i+1];
        	sum = (sum + item) / 2 ;
        }

        System.out.println(sum);



    }
}