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

public class Main {
    public static void main(String[] args) throws Exception {
	
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        OutputStream outputStream = System.out;
    	PrintWriter out = new PrintWriter(outputStream);

        int i, n, m, c, k, j;

		int t = Integer.parseInt(br.readLine());    
        StringTokenizer st = new StringTokenizer(br.readLine());
    	int[] ar = new int[t];
     
		for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken());
      
      Arrays.sort(ar);
         double sum=ar[0],max=0;
        for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        }
	out.print(sum);
	out.flush();
	out.close();
	
	}
} import java.io.*; io.* java import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
	
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        OutputStream outputStream = System.out;
    	PrintWriter out = new PrintWriter(outputStream);

        int i, n, m, c, k, j;

		int t = Integer.parseInt(br.readLine());    
        StringTokenizer st = new StringTokenizer(br.readLine());
    	int[] ar = new int[t];
     
		for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken());
      
      Arrays.sort(ar);
         double sum=ar[0],max=0;
        for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        }
	out.print(sum);
	out.flush();
	out.close();
	
	}
} Main public static void main(String[] args) throws Exception {
	
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        OutputStream outputStream = System.out;
    	PrintWriter out = new PrintWriter(outputStream);

        int i, n, m, c, k, j;

		int t = Integer.parseInt(br.readLine());    
        StringTokenizer st = new StringTokenizer(br.readLine());
    	int[] ar = new int[t];
     
		for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken());
      
      Arrays.sort(ar);
         double sum=ar[0],max=0;
        for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        }
	out.print(sum);
	out.flush();
	out.close();
	
	} main {
	
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        OutputStream outputStream = System.out;
    	PrintWriter out = new PrintWriter(outputStream);

        int i, n, m, c, k, j;

		int t = Integer.parseInt(br.readLine());    
        StringTokenizer st = new StringTokenizer(br.readLine());
    	int[] ar = new int[t];
     
		for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken());
      
      Arrays.sort(ar);
         double sum=ar[0],max=0;
        for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        }
	out.print(sum);
	out.flush();
	out.close();
	
	} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) OutputStream outputStream = System.out; outputStream System.out System System.out PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) int i i n n m m c c k k j; j int t = Integer.parseInt(br.readLine()); t Integer.parseInt(br.readLine()) Integer.parseInt Integer br.readLine() br.readLine br StringTokenizer st = new StringTokenizer(br.readLine()); st new StringTokenizer(br.readLine()) int[] ar = new int[t]; ar new int[t] t for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken()); i=0; i=0 i 0 i<t i t i++ i++ i ar[i]=Integer.parseInt(st.nextToken()); ar[i]=Integer.parseInt(st.nextToken()) ar[i] ar i Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st Arrays.sort(ar) Arrays.sort Arrays ar double sum=ar[0] sum ar[0] ar 0 max=0; max 0 for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        } i=1; i=1 i 1 i<t i t i++ i++ i {
          sum=(sum+ar[i])/2;
        } {
          sum=(sum+ar[i])/2;
        } sum=(sum+ar[i])/2 sum (sum+ar[i])/2 (sum+ar[i]) sum ar[i] ar i 2 out.print(sum) out.print out sum out.flush() out.flush out out.close() out.close out String[] args args public class Main {
    public static void main(String[] args) throws Exception {
	
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        OutputStream outputStream = System.out;
    	PrintWriter out = new PrintWriter(outputStream);

        int i, n, m, c, k, j;

		int t = Integer.parseInt(br.readLine());    
        StringTokenizer st = new StringTokenizer(br.readLine());
    	int[] ar = new int[t];
     
		for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken());
      
      Arrays.sort(ar);
         double sum=ar[0],max=0;
        for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        }
	out.print(sum);
	out.flush();
	out.close();
	
	}
} public class Main {
    public static void main(String[] args) throws Exception {
	
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        OutputStream outputStream = System.out;
    	PrintWriter out = new PrintWriter(outputStream);

        int i, n, m, c, k, j;

		int t = Integer.parseInt(br.readLine());    
        StringTokenizer st = new StringTokenizer(br.readLine());
    	int[] ar = new int[t];
     
		for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken());
      
      Arrays.sort(ar);
         double sum=ar[0],max=0;
        for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        }
	out.print(sum);
	out.flush();
	out.close();
	
	}
} Main
import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
	
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        OutputStream outputStream = System.out;
    	PrintWriter out = new PrintWriter(outputStream);

        int i, n, m, c, k, j;

		int t = Integer.parseInt(br.readLine());    
        StringTokenizer st = new StringTokenizer(br.readLine());
    	int[] ar = new int[t];
     
		for(i=0;i<t;i++)
          ar[i]=Integer.parseInt(st.nextToken());
      
      Arrays.sort(ar);
         double sum=ar[0],max=0;
        for(i=1;i<t;i++)
        {
          sum=(sum+ar[i])/2;
        }
	out.print(sum);
	out.flush();
	out.close();
	
	}
}