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

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        int[] ingredients = new int[N];
        for (int i = 0; i < N; i++) ingredients[i] = in.nextInt();
        Arrays.sort(ingredients);

        float res = (float) (ingredients[0] + ingredients[1]) / 2;
        for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2;
        System.out.println(res);
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        int[] ingredients = new int[N];
        for (int i = 0; i < N; i++) ingredients[i] = in.nextInt();
        Arrays.sort(ingredients);

        float res = (float) (ingredients[0] + ingredients[1]) / 2;
        for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2;
        System.out.println(res);
    }
} Main public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        int[] ingredients = new int[N];
        for (int i = 0; i < N; i++) ingredients[i] = in.nextInt();
        Arrays.sort(ingredients);

        float res = (float) (ingredients[0] + ingredients[1]) / 2;
        for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2;
        System.out.println(res);
    } main {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        int[] ingredients = new int[N];
        for (int i = 0; i < N; i++) ingredients[i] = in.nextInt();
        Arrays.sort(ingredients);

        float res = (float) (ingredients[0] + ingredients[1]) / 2;
        for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2;
        System.out.println(res);
    } Scanner in = new Scanner(System.in); in new Scanner(System.in) int N = in.nextInt(); N in.nextInt() in.nextInt in int[] ingredients = new int[N]; ingredients new int[N] N for (int i = 0; i < N; i++) ingredients[i] = in.nextInt(); int i = 0; int i = 0; i 0 i < N i N i++ i++ i ingredients[i] = in.nextInt(); ingredients[i] = in.nextInt() ingredients[i] ingredients i in.nextInt() in.nextInt in Arrays.sort(ingredients) Arrays.sort Arrays ingredients float res = (float) (ingredients[0] + ingredients[1]) / 2; res (float) (ingredients[0] + ingredients[1]) / 2 (float) (ingredients[0] + ingredients[1]) ingredients[0] ingredients 0 ingredients[1] ingredients 1 2 for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2; int i = 2; int i = 2; i 2 i < N i N i++ i++ i res = (res + ingredients[i]) / 2; res = (res + ingredients[i]) / 2 res (res + ingredients[i]) / 2 (res + ingredients[i]) res ingredients[i] ingredients i 2 System.out.println(res) System.out.println System.out System System.out res String[] args args public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        int[] ingredients = new int[N];
        for (int i = 0; i < N; i++) ingredients[i] = in.nextInt();
        Arrays.sort(ingredients);

        float res = (float) (ingredients[0] + ingredients[1]) / 2;
        for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2;
        System.out.println(res);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        int[] ingredients = new int[N];
        for (int i = 0; i < N; i++) ingredients[i] = in.nextInt();
        Arrays.sort(ingredients);

        float res = (float) (ingredients[0] + ingredients[1]) / 2;
        for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2;
        System.out.println(res);
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        int[] ingredients = new int[N];
        for (int i = 0; i < N; i++) ingredients[i] = in.nextInt();
        Arrays.sort(ingredients);

        float res = (float) (ingredients[0] + ingredients[1]) / 2;
        for (int i = 2; i < N; i++) res = (res + ingredients[i]) / 2;
        System.out.println(res);
    }
}
