import java.util.*;
import java.io.*;

class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        int a[] = new int[n];
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(st.nextToken());
        }

        Arrays.sort(a);

        double d = a[0];
        for (int i = 1; i < n; i++) {
            d = (d + a[i]) / 2;
        }

        System.out.println(d);
    }
} import java.util.*; util.* java import java.io.*; io.* java class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        int a[] = new int[n];
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(st.nextToken());
        }

        Arrays.sort(a);

        double d = a[0];
        for (int i = 1; i < n; i++) {
            d = (d + a[i]) / 2;
        }

        System.out.println(d);
    }
} Main public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        int a[] = new int[n];
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(st.nextToken());
        }

        Arrays.sort(a);

        double d = a[0];
        for (int i = 1; i < n; i++) {
            d = (d + a[i]) / 2;
        }

        System.out.println(d);
    } main {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        int a[] = new int[n];
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(st.nextToken());
        }

        Arrays.sort(a);

        double d = a[0];
        for (int i = 1; i < n; i++) {
            d = (d + a[i]) / 2;
        }

        System.out.println(d);
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) StringTokenizer st; st int n = Integer.parseInt(br.readLine()); n Integer.parseInt(br.readLine()) Integer.parseInt Integer br.readLine() br.readLine br int a[] = new int[n]; a new int[n] n st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(st.nextToken());
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            a[i] = Integer.parseInt(st.nextToken());
        } {
            a[i] = Integer.parseInt(st.nextToken());
        } a[i] = Integer.parseInt(st.nextToken()) a[i] a i Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st Arrays.sort(a) Arrays.sort Arrays a double d = a[0]; d a[0] a 0 for (int i = 1; i < n; i++) {
            d = (d + a[i]) / 2;
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            d = (d + a[i]) / 2;
        } {
            d = (d + a[i]) / 2;
        } d = (d + a[i]) / 2 d (d + a[i]) / 2 (d + a[i]) d a[i] a i 2 System.out.println(d) System.out.println System.out System System.out d String[] args args
import java.util.*;
import java.io.*;

class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        int a[] = new int[n];
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(st.nextToken());
        }

        Arrays.sort(a);

        double d = a[0];
        for (int i = 1; i < n; i++) {
            d = (d + a[i]) / 2;
        }

        System.out.println(d);
    }
}
