import java.util.*;
import java.lang.*;
class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      	int num = sc.nextInt();
      	double[] ary = new double[num];
      	for(int i = 0; i < num; i++){
      		ary[i] = sc.nextDouble();
      	}
      	Arrays.sort(ary);
  		double result = ary[0];
      	for(int j = 1; j < num; j++){
          result = (result + ary[j])/2.0;
      	}
      	System.out.println(result);
  	}
} import java.util.*; util.* java import java.lang.*; lang.* java class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      	int num = sc.nextInt();
      	double[] ary = new double[num];
      	for(int i = 0; i < num; i++){
      		ary[i] = sc.nextDouble();
      	}
      	Arrays.sort(ary);
  		double result = ary[0];
      	for(int j = 1; j < num; j++){
          result = (result + ary[j])/2.0;
      	}
      	System.out.println(result);
  	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      	int num = sc.nextInt();
      	double[] ary = new double[num];
      	for(int i = 0; i < num; i++){
      		ary[i] = sc.nextDouble();
      	}
      	Arrays.sort(ary);
  		double result = ary[0];
      	for(int j = 1; j < num; j++){
          result = (result + ary[j])/2.0;
      	}
      	System.out.println(result);
  	} main {
		Scanner sc = new Scanner(System.in);
      	int num = sc.nextInt();
      	double[] ary = new double[num];
      	for(int i = 0; i < num; i++){
      		ary[i] = sc.nextDouble();
      	}
      	Arrays.sort(ary);
  		double result = ary[0];
      	for(int j = 1; j < num; j++){
          result = (result + ary[j])/2.0;
      	}
      	System.out.println(result);
  	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int num = sc.nextInt(); num sc.nextInt() sc.nextInt sc double[] ary = new double[num]; ary new double[num] num for(int i = 0; i < num; i++){
      		ary[i] = sc.nextDouble();
      	} int i = 0; int i = 0; i 0 i < num i num i++ i++ i {
      		ary[i] = sc.nextDouble();
      	} {
      		ary[i] = sc.nextDouble();
      	} ary[i] = sc.nextDouble() ary[i] ary i sc.nextDouble() sc.nextDouble sc Arrays.sort(ary) Arrays.sort Arrays ary double result = ary[0]; result ary[0] ary 0 for(int j = 1; j < num; j++){
          result = (result + ary[j])/2.0;
      	} int j = 1; int j = 1; j 1 j < num j num j++ j++ j {
          result = (result + ary[j])/2.0;
      	} {
          result = (result + ary[j])/2.0;
      	} result = (result + ary[j])/2.0 result (result + ary[j])/2.0 (result + ary[j]) result ary[j] ary j 2.0 System.out.println(result) System.out.println System.out System System.out result String[] args args
import java.util.*;
import java.lang.*;
class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      	int num = sc.nextInt();
      	double[] ary = new double[num];
      	for(int i = 0; i < num; i++){
      		ary[i] = sc.nextDouble();
      	}
      	Arrays.sort(ary);
  		double result = ary[0];
      	for(int j = 1; j < num; j++){
          result = (result + ary[j])/2.0;
      	}
      	System.out.println(result);
  	}
}