import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] v = new int[N];
    PriorityQueue<Integer> queue = new PriorityQueue<>();
    for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    }
    float ans = queue.poll();
    while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 2;
    }
    System.out.println(ans);
  }
} import java.util.PriorityQueue; PriorityQueue java.util import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] v = new int[N];
    PriorityQueue<Integer> queue = new PriorityQueue<>();
    for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    }
    float ans = queue.poll();
    while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 2;
    }
    System.out.println(ans);
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] v = new int[N];
    PriorityQueue<Integer> queue = new PriorityQueue<>();
    for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    }
    float ans = queue.poll();
    while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 2;
    }
    System.out.println(ans);
  } main {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] v = new int[N];
    PriorityQueue<Integer> queue = new PriorityQueue<>();
    for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    }
    float ans = queue.poll();
    while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 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[] v = new int[N]; v new int[N] N PriorityQueue<Integer> queue = new PriorityQueue<>(); queue new PriorityQueue<>() for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
      queue.add(sc.nextInt());
    } {
      queue.add(sc.nextInt());
    } queue.add(sc.nextInt()) queue.add queue sc.nextInt() sc.nextInt sc float ans = queue.poll(); ans queue.poll() queue.poll queue while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 2;
    } !queue.isEmpty() queue.isEmpty() queue.isEmpty queue {
      ans = (ans + queue.poll()) / 2;
    } ans = (ans + queue.poll()) / 2 ans (ans + queue.poll()) / 2 (ans + queue.poll()) ans queue.poll() queue.poll queue 2 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] v = new int[N];
    PriorityQueue<Integer> queue = new PriorityQueue<>();
    for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    }
    float ans = queue.poll();
    while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 2;
    }
    System.out.println(ans);
  }
} public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] v = new int[N];
    PriorityQueue<Integer> queue = new PriorityQueue<>();
    for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    }
    float ans = queue.poll();
    while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 2;
    }
    System.out.println(ans);
  }
} Main
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] v = new int[N];
    PriorityQueue<Integer> queue = new PriorityQueue<>();
    for (int i = 0; i < N; i++) {
      queue.add(sc.nextInt());
    }
    float ans = queue.poll();
    while (!queue.isEmpty()) {
      ans = (ans + queue.poll()) / 2;
    }
    System.out.println(ans);
  }
}