import java.io.*;
import java.util.*;
public class Main{
  public static void main(String[]args){
  Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] a=new int[n];
  	for(int i=0;i<n;i++)a[i]=sc.nextInt();
    Arrays.sort(a);
    double value=a[0];
    for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    }
    System.out.println(value);
  }
} import java.io.*; io.* java import java.util.*; util.* java public class Main{
  public static void main(String[]args){
  Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] a=new int[n];
  	for(int i=0;i<n;i++)a[i]=sc.nextInt();
    Arrays.sort(a);
    double value=a[0];
    for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    }
    System.out.println(value);
  }
} Main public static void main(String[]args){
  Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] a=new int[n];
  	for(int i=0;i<n;i++)a[i]=sc.nextInt();
    Arrays.sort(a);
    double value=a[0];
    for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    }
    System.out.println(value);
  } main {
  Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] a=new int[n];
  	for(int i=0;i<n;i++)a[i]=sc.nextInt();
    Arrays.sort(a);
    double value=a[0];
    for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    }
    System.out.println(value);
  } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int n=sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] a=new int[n]; a new int[n] n for(int i=0;i<n;i++)a[i]=sc.nextInt(); int i=0; int i=0; i 0 i<n i n i++ i++ i a[i]=sc.nextInt(); a[i]=sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc Arrays.sort(a) Arrays.sort Arrays a double value=a[0]; value a[0] a 0 for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    } int i=0; int i=0; i 0 i<n i n i++ i++ i {
   	value=(value+a[i])/2;
    } {
   	value=(value+a[i])/2;
    } value=(value+a[i])/2 value (value+a[i])/2 (value+a[i]) value a[i] a i 2 System.out.println(value) System.out.println System.out System System.out value String[]args args public class Main{
  public static void main(String[]args){
  Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] a=new int[n];
  	for(int i=0;i<n;i++)a[i]=sc.nextInt();
    Arrays.sort(a);
    double value=a[0];
    for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    }
    System.out.println(value);
  }
} public class Main{
  public static void main(String[]args){
  Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] a=new int[n];
  	for(int i=0;i<n;i++)a[i]=sc.nextInt();
    Arrays.sort(a);
    double value=a[0];
    for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    }
    System.out.println(value);
  }
} Main
import java.io.*;
import java.util.*;
public class Main{
  public static void main(String[]args){
  Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int[] a=new int[n];
  	for(int i=0;i<n;i++)a[i]=sc.nextInt();
    Arrays.sort(a);
    double value=a[0];
    for(int i=0;i<n;i++){
   	value=(value+a[i])/2;
    }
    System.out.println(value);
  }
}