import java.util.*;

class Main {
    //
    static final long MOD = 1_000_000_007; // 10^9+7
    static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9

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

} import java.util.*; util.* java class Main {
    //
    static final long MOD = 1_000_000_007; // 10^9+7
    static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9

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

} Main //
    static final long MOD = 1_000_000_007; // 10^9+7 MOD 1_000_000_007 static final int MAX = 2_147_483_646; // intの最大値 MAX 2_147_483_646 static final int INF = 1_000_000_000; // 10^9 INF 1_000_000_000 public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] ary = new int[n];
        for (int i = 0; i < n; i++) {
            ary[i] = sc.nextInt();
        }
        Arrays.sort(ary);
        double ans = ary[0];
        for(int i = 1;i < n;i++){
            ans = ans + ary[i];
            ans /= 2;
        }
        System.out.println(ans);
        
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] ary = new int[n];
        for (int i = 0; i < n; i++) {
            ary[i] = sc.nextInt();
        }
        Arrays.sort(ary);
        double ans = ary[0];
        for(int i = 1;i < n;i++){
            ans = ans + ary[i];
            ans /= 2;
        }
        System.out.println(ans);
        
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] ary = new int[n]; ary new int[n] n for (int i = 0; i < n; i++) {
            ary[i] = sc.nextInt();
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            ary[i] = sc.nextInt();
        } {
            ary[i] = sc.nextInt();
        } ary[i] = sc.nextInt() ary[i] ary i sc.nextInt() sc.nextInt sc Arrays.sort(ary) Arrays.sort Arrays ary double ans = ary[0]; ans ary[0] ary 0 for(int i = 1;i < n;i++){
            ans = ans + ary[i];
            ans /= 2;
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            ans = ans + ary[i];
            ans /= 2;
        } {
            ans = ans + ary[i];
            ans /= 2;
        } ans = ans + ary[i] ans ans + ary[i] ans ary[i] ary i ans /= 2 ans 2 System.out.println(ans) System.out.println System.out System System.out ans String args[] args
import java.util.*;

class Main {
    //
    static final long MOD = 1_000_000_007; // 10^9+7
    static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9

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

}