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

public class Main {

  public static void main(String[] args) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    float v[] = new float[n];
    for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    }

    Arrays.sort(v);

    float avg = v[0];
    for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    }
    System.out.println(avg);
  }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

  public static void main(String[] args) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    float v[] = new float[n];
    for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    }

    Arrays.sort(v);

    float avg = v[0];
    for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    }
    System.out.println(avg);
  }
} Main public static void main(String[] args) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    float v[] = new float[n];
    for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    }

    Arrays.sort(v);

    float avg = v[0];
    for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    }
    System.out.println(avg);
  } main {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    float v[] = new float[n];
    for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    }

    Arrays.sort(v);

    float avg = v[0];
    for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    }
    System.out.println(avg);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc float v[] = new float[n]; v new float[n] n for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
      v[i] = sc.nextFloat();
    } {
      v[i] = sc.nextFloat();
    } v[i] = sc.nextFloat() v[i] v i sc.nextFloat() sc.nextFloat sc Arrays.sort(v) Arrays.sort Arrays v float avg = v[0]; avg v[0] v 0 for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
      avg = (avg + v[i]) / 2;
    } {
      avg = (avg + v[i]) / 2;
    } avg = (avg + v[i]) / 2 avg (avg + v[i]) / 2 (avg + v[i]) avg v[i] v i 2 System.out.println(avg) System.out.println System.out System System.out avg String[] args args public class Main {

  public static void main(String[] args) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    float v[] = new float[n];
    for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    }

    Arrays.sort(v);

    float avg = v[0];
    for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    }
    System.out.println(avg);
  }
} public class Main {

  public static void main(String[] args) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    float v[] = new float[n];
    for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    }

    Arrays.sort(v);

    float avg = v[0];
    for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    }
    System.out.println(avg);
  }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    // TODO 自動生成されたメソッド・スタブ
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    float v[] = new float[n];
    for (int i = 0; i < n; i++) {
      v[i] = sc.nextFloat();
    }

    Arrays.sort(v);

    float avg = v[0];
    for (int i = 1; i < n; i++) {
      avg = (avg + v[i]) / 2;
    }
    System.out.println(avg);
  }
}
