import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        List<BigDecimal> list = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        }
        list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList());

        BigDecimal result = list.get(0);
        for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        }

        System.out.println(result.toPlainString());
        sc.close();
    }
} import java.math.BigDecimal; BigDecimal java.math import java.math.RoundingMode; RoundingMode java.math import java.util.ArrayList; ArrayList java.util import java.util.Comparator; Comparator java.util import java.util.List; List java.util import java.util.Scanner; Scanner java.util import java.util.stream.Collectors; Collectors java.util.stream public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        List<BigDecimal> list = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        }
        list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList());

        BigDecimal result = list.get(0);
        for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        }

        System.out.println(result.toPlainString());
        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        List<BigDecimal> list = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        }
        list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList());

        BigDecimal result = list.get(0);
        for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        }

        System.out.println(result.toPlainString());
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        List<BigDecimal> list = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        }
        list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList());

        BigDecimal result = list.get(0);
        for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        }

        System.out.println(result.toPlainString());
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = Integer.parseInt(sc.next()); N Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc List<BigDecimal> list = new ArrayList<>(); list new ArrayList<>() for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            list.add(new BigDecimal(sc.next()));
        } {
            list.add(new BigDecimal(sc.next()));
        } list.add(new BigDecimal(sc.next())) list.add list new BigDecimal(sc.next()) list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList()) list list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList()) list.stream().sorted(Comparator.naturalOrder()).collect list.stream().sorted(Comparator.naturalOrder()) list.stream().sorted list.stream() list.stream list Comparator.naturalOrder() Comparator.naturalOrder Comparator Collectors.toList() Collectors.toList Collectors BigDecimal result = list.get(0); result list.get(0) list.get list 0 for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        } int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        } {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        } BigDecimal sum = result.add(list.get(i)); sum result.add(list.get(i)) result.add result list.get(i) list.get list i result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN) result sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN) sum.divide sum new BigDecimal("2") 7 RoundingMode.HALF_EVEN RoundingMode RoundingMode.HALF_EVEN System.out.println(result.toPlainString()) System.out.println System.out System System.out result.toPlainString() result.toPlainString result sc.close() sc.close sc String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        List<BigDecimal> list = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        }
        list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList());

        BigDecimal result = list.get(0);
        for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        }

        System.out.println(result.toPlainString());
        sc.close();
    }
} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        List<BigDecimal> list = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        }
        list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList());

        BigDecimal result = list.get(0);
        for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        }

        System.out.println(result.toPlainString());
        sc.close();
    }
} Main
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        List<BigDecimal> list = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            list.add(new BigDecimal(sc.next()));
        }
        list = list.stream().sorted(Comparator.naturalOrder()).collect(Collectors.toList());

        BigDecimal result = list.get(0);
        for (int i = 1; i < N; i++) {
            BigDecimal sum = result.add(list.get(i));

            result = sum.divide(new BigDecimal("2"), 7, RoundingMode.HALF_EVEN);
        }

        System.out.println(result.toPlainString());
        sc.close();
    }
}