import java.util.*;
public class Main {
    public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);

      //入力
      int g =sc.nextInt();//具材の数
      int val[] = new int[g];
      
      //具の価値を配列へ
      for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      }
      //昇順に並び替え
      Arrays.sort(val);
      
      double ans = val[0];
      
      for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      }
      System.out.println(ans);
    }
}
       import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);

      //入力
      int g =sc.nextInt();//具材の数
      int val[] = new int[g];
      
      //具の価値を配列へ
      for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      }
      //昇順に並び替え
      Arrays.sort(val);
      
      double ans = val[0];
      
      for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      }
      System.out.println(ans);
    }
} Main public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);

      //入力
      int g =sc.nextInt();//具材の数
      int val[] = new int[g];
      
      //具の価値を配列へ
      for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      }
      //昇順に並び替え
      Arrays.sort(val);
      
      double ans = val[0];
      
      for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      }
      System.out.println(ans);
    } main {
    
    Scanner sc = new Scanner(System.in);

      //入力
      int g =sc.nextInt();//具材の数
      int val[] = new int[g];
      
      //具の価値を配列へ
      for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      }
      //昇順に並び替え
      Arrays.sort(val);
      
      double ans = val[0];
      
      for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      }
      System.out.println(ans);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int g =sc.nextInt(); g sc.nextInt() sc.nextInt sc int val[] = new int[g]; val new int[g] g for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      } int i =0; int i =0; i 0 i<g i g i++ i++ i {
        	val[i] = sc.nextInt();
      } {
        	val[i] = sc.nextInt();
      } val[i] = sc.nextInt() val[i] val i sc.nextInt() sc.nextInt sc Arrays.sort(val) Arrays.sort Arrays val double ans = val[0]; ans val[0] val 0 for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      } int i=1; int i=1; i 1 i<g i g i++ i++ i {
        	 ans = (ans+val[i])/2.0;
      } {
        	 ans = (ans+val[i])/2.0;
      } ans = (ans+val[i])/2.0 ans (ans+val[i])/2.0 (ans+val[i]) ans val[i] val i 2.0 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);

      //入力
      int g =sc.nextInt();//具材の数
      int val[] = new int[g];
      
      //具の価値を配列へ
      for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      }
      //昇順に並び替え
      Arrays.sort(val);
      
      double ans = val[0];
      
      for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      }
      System.out.println(ans);
    }
} public class Main {
    public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);

      //入力
      int g =sc.nextInt();//具材の数
      int val[] = new int[g];
      
      //具の価値を配列へ
      for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      }
      //昇順に並び替え
      Arrays.sort(val);
      
      double ans = val[0];
      
      for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      }
      System.out.println(ans);
    }
} Main
import java.util.*;
public class Main {
    public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);

      //入力
      int g =sc.nextInt();//具材の数
      int val[] = new int[g];
      
      //具の価値を配列へ
      for(int i =0; i<g; i++){
        	val[i] = sc.nextInt();
      }
      //昇順に並び替え
      Arrays.sort(val);
      
      double ans = val[0];
      
      for(int i=1; i<g; i++){
        	 ans = (ans+val[i])/2.0;
      }
      System.out.println(ans);
    }
}
      