import java.util.*;
public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int N = scan.nextInt();
    int[] A;
    A = new int[N+1];
    
    // ソートする
    for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    }
    Arrays.sort(A);
    float result=A[1];
    for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    }
    System.out.println(result);
  
  }
 
} import java.util.*; util.* java public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int N = scan.nextInt();
    int[] A;
    A = new int[N+1];
    
    // ソートする
    for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    }
    Arrays.sort(A);
    float result=A[1];
    for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    }
    System.out.println(result);
  
  }
 
} Main public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int N = scan.nextInt();
    int[] A;
    A = new int[N+1];
    
    // ソートする
    for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    }
    Arrays.sort(A);
    float result=A[1];
    for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    }
    System.out.println(result);
  
  } main {
    Scanner scan = new Scanner(System.in);
    int N = scan.nextInt();
    int[] A;
    A = new int[N+1];
    
    // ソートする
    for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    }
    Arrays.sort(A);
    float result=A[1];
    for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    }
    System.out.println(result);
  
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int N = scan.nextInt(); N scan.nextInt() scan.nextInt scan int[] A; A A = new int[N+1] A new int[N+1] N+1 N 1 for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    } int i= 1; int i= 1; i 1 i <= N i N i++ i++ i {
      A[i] = scan.nextInt();
    } {
      A[i] = scan.nextInt();
    } A[i] = scan.nextInt() A[i] A i scan.nextInt() scan.nextInt scan Arrays.sort(A) Arrays.sort Arrays A float result=A[1]; result A[1] A 1 for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    } int j= 2; int j= 2; j 2 j <= N j N j++ j++ j {
      result=result/2+(float)A[j]/2;
    } {
      result=result/2+(float)A[j]/2;
    } result=result/2+(float)A[j]/2 result result/2+(float)A[j]/2 result/2 result 2 (float)A[j]/2 (float)A[j] A j 2 System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int N = scan.nextInt();
    int[] A;
    A = new int[N+1];
    
    // ソートする
    for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    }
    Arrays.sort(A);
    float result=A[1];
    for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    }
    System.out.println(result);
  
  }
 
} public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int N = scan.nextInt();
    int[] A;
    A = new int[N+1];
    
    // ソートする
    for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    }
    Arrays.sort(A);
    float result=A[1];
    for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    }
    System.out.println(result);
  
  }
 
} Main
import java.util.*;
public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int N = scan.nextInt();
    int[] A;
    A = new int[N+1];
    
    // ソートする
    for (int i= 1; i <= N; i++){
      A[i] = scan.nextInt();
    }
    Arrays.sort(A);
    float result=A[1];
    for (int j= 2; j <= N; j++){
      result=result/2+(float)A[j]/2;
    }
    System.out.println(result);
  
  }
 
}