import java.io.*;
import java.util.*;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next());
    int[] v = new int[N];
    for (int i = 0; i < N; i++) {
      v[i] = Integer.parseInt(sc.next());
    }
    
    Arrays.sort(v);
    
    double sum = v[0];
    for (int i = 1; i < N; i++) {
      sum = (sum + v[i]) / 2.0;
    }
    
    System.out.println(sum);
  }
} import java.io.*; io.* java import java.util.*; util.* java class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next());
    int[] v = new int[N];
    for (int i = 0; i < N; i++) {
      v[i] = Integer.parseInt(sc.next());
    }
    
    Arrays.sort(v);
    
    double sum = v[0];
    for (int i = 1; i < N; i++) {
      sum = (sum + v[i]) / 2.0;
    }
    
    System.out.println(sum);
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next());
    int[] v = new int[N];
    for (int i = 0; i < N; i++) {
      v[i] = Integer.parseInt(sc.next());
    }
    
    Arrays.sort(v);
    
    double sum = v[0];
    for (int i = 1; i < N; i++) {
      sum = (sum + v[i]) / 2.0;
    }
    
    System.out.println(sum);
  } main {
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next());
    int[] v = new int[N];
    for (int i = 0; i < N; i++) {
      v[i] = Integer.parseInt(sc.next());
    }
    
    Arrays.sort(v);
    
    double sum = v[0];
    for (int i = 1; i < N; i++) {
      sum = (sum + v[i]) / 2.0;
    }
    
    System.out.println(sum);
  } 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 int[] v = new int[N]; v new int[N] N for (int i = 0; i < N; i++) {
      v[i] = Integer.parseInt(sc.next());
    } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
      v[i] = Integer.parseInt(sc.next());
    } {
      v[i] = Integer.parseInt(sc.next());
    } v[i] = Integer.parseInt(sc.next()) v[i] v i Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc Arrays.sort(v) Arrays.sort Arrays v double sum = v[0]; sum v[0] v 0 for (int i = 1; i < N; i++) {
      sum = (sum + v[i]) / 2.0;
    } int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
      sum = (sum + v[i]) / 2.0;
    } {
      sum = (sum + v[i]) / 2.0;
    } sum = (sum + v[i]) / 2.0 sum (sum + v[i]) / 2.0 (sum + v[i]) sum v[i] v i 2.0 System.out.println(sum) System.out.println System.out System System.out sum String[] args args
import java.io.*;
import java.util.*;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.next());
    int[] v = new int[N];
    for (int i = 0; i < N; i++) {
      v[i] = Integer.parseInt(sc.next());
    }
    
    Arrays.sort(v);
    
    double sum = v[0];
    for (int i = 1; i < N; i++) {
      sum = (sum + v[i]) / 2.0;
    }
    
    System.out.println(sum);
  }
}