import java.util.*; 

class Main{
public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
       
  		int[] v=new int[n];
		for(int c=0;c<n;c++){
    		v[c]=sc.nextInt();
    	}
  	Arrays.sort(v);
  	double ans=(double)v[0];
    
 	for(int d=1;d<n;d++){
      ans=(ans+v[d])/2;
    
    }

    	System.out.println(ans);
    }
}
 import java.util.*; util.* java class Main{
public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
       
  		int[] v=new int[n];
		for(int c=0;c<n;c++){
    		v[c]=sc.nextInt();
    	}
  	Arrays.sort(v);
  	double ans=(double)v[0];
    
 	for(int d=1;d<n;d++){
      ans=(ans+v[d])/2;
    
    }

    	System.out.println(ans);
    }
} Main public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
       
  		int[] v=new int[n];
		for(int c=0;c<n;c++){
    		v[c]=sc.nextInt();
    	}
  	Arrays.sort(v);
  	double ans=(double)v[0];
    
 	for(int d=1;d<n;d++){
      ans=(ans+v[d])/2;
    
    }

    	System.out.println(ans);
    } main {
	Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
       
  		int[] v=new int[n];
		for(int c=0;c<n;c++){
    		v[c]=sc.nextInt();
    	}
  	Arrays.sort(v);
  	double ans=(double)v[0];
    
 	for(int d=1;d<n;d++){
      ans=(ans+v[d])/2;
    
    }

    	System.out.println(ans);
    } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int n=sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] v=new int[n]; v new int[n] n for(int c=0;c<n;c++){
    		v[c]=sc.nextInt();
    	} int c=0; int c=0; c 0 c<n c n c++ c++ c {
    		v[c]=sc.nextInt();
    	} {
    		v[c]=sc.nextInt();
    	} v[c]=sc.nextInt() v[c] v c sc.nextInt() sc.nextInt sc Arrays.sort(v) Arrays.sort Arrays v double ans=(double)v[0]; ans (double)v[0] v 0 for(int d=1;d<n;d++){
      ans=(ans+v[d])/2;
    
    } int d=1; int d=1; d 1 d<n d n d++ d++ d {
      ans=(ans+v[d])/2;
    
    } {
      ans=(ans+v[d])/2;
    
    } ans=(ans+v[d])/2 ans (ans+v[d])/2 (ans+v[d]) ans v[d] v d 2 System.out.println(ans) System.out.println System.out System System.out ans String[] args args
import java.util.*; 

class Main{
public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
       
  		int[] v=new int[n];
		for(int c=0;c<n;c++){
    		v[c]=sc.nextInt();
    	}
  	Arrays.sort(v);
  	double ans=(double)v[0];
    
 	for(int d=1;d<n;d++){
      ans=(ans+v[d])/2;
    
    }

    	System.out.println(ans);
    }
}

