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


public class Main {
	public static void main(String [] args) throws IOException
	  {
	    InputStreamReader ir=new InputStreamReader(System.in);
	    BufferedReader br=new BufferedReader(ir);
	    int n=Integer.parseInt(br.readLine());
	    String [] s=br.readLine().split(" ");
	    int arr[]=new int[n];
	    for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    }
	    Arrays.sort(arr);
	    double value=arr[0];
	    for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    }
	    System.out.println(value);
	  }
} import java.io.*; io.* java import java.util.Arrays; Arrays java.util public class Main {
	public static void main(String [] args) throws IOException
	  {
	    InputStreamReader ir=new InputStreamReader(System.in);
	    BufferedReader br=new BufferedReader(ir);
	    int n=Integer.parseInt(br.readLine());
	    String [] s=br.readLine().split(" ");
	    int arr[]=new int[n];
	    for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    }
	    Arrays.sort(arr);
	    double value=arr[0];
	    for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    }
	    System.out.println(value);
	  }
} Main public static void main(String [] args) throws IOException
	  {
	    InputStreamReader ir=new InputStreamReader(System.in);
	    BufferedReader br=new BufferedReader(ir);
	    int n=Integer.parseInt(br.readLine());
	    String [] s=br.readLine().split(" ");
	    int arr[]=new int[n];
	    for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    }
	    Arrays.sort(arr);
	    double value=arr[0];
	    for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    }
	    System.out.println(value);
	  } main {
	    InputStreamReader ir=new InputStreamReader(System.in);
	    BufferedReader br=new BufferedReader(ir);
	    int n=Integer.parseInt(br.readLine());
	    String [] s=br.readLine().split(" ");
	    int arr[]=new int[n];
	    for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    }
	    Arrays.sort(arr);
	    double value=arr[0];
	    for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    }
	    System.out.println(value);
	  } InputStreamReader ir=new InputStreamReader(System.in); ir new InputStreamReader(System.in) BufferedReader br=new BufferedReader(ir); br new BufferedReader(ir) 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 " " int arr[]=new int[n]; arr new int[n] n for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    } int i=0; int i=0; i 0 i<n i n i++ i++ i {
	    	arr[i]=Integer.parseInt(s[i]);
	    } {
	    	arr[i]=Integer.parseInt(s[i]);
	    } arr[i]=Integer.parseInt(s[i]) arr[i] arr i Integer.parseInt(s[i]) Integer.parseInt Integer s[i] s i Arrays.sort(arr) Arrays.sort Arrays arr double value=arr[0]; value arr[0] arr 0 for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    } int i=1; int i=1; i 1 i<n i n i++ i++ i {
	    	value=((double)value+arr[i])/2;
	    } {
	    	value=((double)value+arr[i])/2;
	    } value=((double)value+arr[i])/2 value ((double)value+arr[i])/2 ((double)value+arr[i]) (double)value arr[i] arr 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) throws IOException
	  {
	    InputStreamReader ir=new InputStreamReader(System.in);
	    BufferedReader br=new BufferedReader(ir);
	    int n=Integer.parseInt(br.readLine());
	    String [] s=br.readLine().split(" ");
	    int arr[]=new int[n];
	    for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    }
	    Arrays.sort(arr);
	    double value=arr[0];
	    for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    }
	    System.out.println(value);
	  }
} public class Main {
	public static void main(String [] args) throws IOException
	  {
	    InputStreamReader ir=new InputStreamReader(System.in);
	    BufferedReader br=new BufferedReader(ir);
	    int n=Integer.parseInt(br.readLine());
	    String [] s=br.readLine().split(" ");
	    int arr[]=new int[n];
	    for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    }
	    Arrays.sort(arr);
	    double value=arr[0];
	    for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    }
	    System.out.println(value);
	  }
} Main
import java.io.*;
import java.util.Arrays;


public class Main {
	public static void main(String [] args) throws IOException
	  {
	    InputStreamReader ir=new InputStreamReader(System.in);
	    BufferedReader br=new BufferedReader(ir);
	    int n=Integer.parseInt(br.readLine());
	    String [] s=br.readLine().split(" ");
	    int arr[]=new int[n];
	    for(int i=0;i<n;i++)
	    {
	    	arr[i]=Integer.parseInt(s[i]);
	    }
	    Arrays.sort(arr);
	    double value=arr[0];
	    for(int i=1;i<n;i++)
	    {
	    	value=((double)value+arr[i])/2;
	    }
	    System.out.println(value);
	  }
}
