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

public class Main
{
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
		int n=Integer.parseInt(br.readLine());
		String []s=br.readLine().split(" ");
		
		double a[]=new double[n];
		
		for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]);
					
					
		Arrays.sort(a);
		
		double sum=a[0];
		
		for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0);
			
		System.out.println(sum);	
		
	}
}

 import java.io.*; io.* java import java.util.*; util.* java public class Main
{
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
		int n=Integer.parseInt(br.readLine());
		String []s=br.readLine().split(" ");
		
		double a[]=new double[n];
		
		for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]);
					
					
		Arrays.sort(a);
		
		double sum=a[0];
		
		for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0);
			
		System.out.println(sum);	
		
	}
} Main public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
		int n=Integer.parseInt(br.readLine());
		String []s=br.readLine().split(" ");
		
		double a[]=new double[n];
		
		for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]);
					
					
		Arrays.sort(a);
		
		double sum=a[0];
		
		for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0);
			
		System.out.println(sum);	
		
	} main {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
		int n=Integer.parseInt(br.readLine());
		String []s=br.readLine().split(" ");
		
		double a[]=new double[n];
		
		for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]);
					
					
		Arrays.sort(a);
		
		double sum=a[0];
		
		for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0);
			
		System.out.println(sum);	
		
	} BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) int n=Integer.parseInt(br.readLine()); n Integer.parseInt(br.readLine()) Integer.parseInt Integer br.readLine() br.readLine br String []s=br.readLine().split(" "); s br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " double a[]=new double[n]; a new double[n] n for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]); int i=0; int i=0; i 0 i<n i n i++ i++ i a[i]=Double.parseDouble(s[i]); a[i]=Double.parseDouble(s[i]) a[i] a i Double.parseDouble(s[i]) Double.parseDouble Double s[i] s i Arrays.sort(a) Arrays.sort Arrays a double sum=a[0]; sum a[0] a 0 for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0); int i=1; int i=1; i 1 i<n i n i++ i++ i sum=((sum+a[i])/2.0); sum=((sum+a[i])/2.0) sum ((sum+a[i])/2.0) (sum+a[i]) sum a[i] a i 2.0 System.out.println(sum) System.out.println System.out System System.out sum String []args args public class Main
{
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
		int n=Integer.parseInt(br.readLine());
		String []s=br.readLine().split(" ");
		
		double a[]=new double[n];
		
		for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]);
					
					
		Arrays.sort(a);
		
		double sum=a[0];
		
		for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0);
			
		System.out.println(sum);	
		
	}
} public class Main
{
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
		int n=Integer.parseInt(br.readLine());
		String []s=br.readLine().split(" ");
		
		double a[]=new double[n];
		
		for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]);
					
					
		Arrays.sort(a);
		
		double sum=a[0];
		
		for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0);
			
		System.out.println(sum);	
		
	}
} Main

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

public class Main
{
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
		int n=Integer.parseInt(br.readLine());
		String []s=br.readLine().split(" ");
		
		double a[]=new double[n];
		
		for(int i=0;i<n;i++)
			a[i]=Double.parseDouble(s[i]);
					
					
		Arrays.sort(a);
		
		double sum=a[0];
		
		for(int i=1;i<n;i++)
			sum=((sum+a[i])/2.0);
			
		System.out.println(sum);	
		
	}
}


