import java.util.Scanner;
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 i=0;i<N;i++){
      v[i] = sc.nextInt();
    }
    
    Arrays.sort(v);
    double sum = 0;
    for(int j=0;j<N;j++){
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    }
    System.out.println(sum);
    
  }
} import java.util.Scanner; Scanner java.util 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 i=0;i<N;i++){
      v[i] = sc.nextInt();
    }
    
    Arrays.sort(v);
    double sum = 0;
    for(int j=0;j<N;j++){
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    }
    System.out.println(sum);
    
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int v[] = new int[N];
    
    for(int i=0;i<N;i++){
      v[i] = sc.nextInt();
    }
    
    Arrays.sort(v);
    double sum = 0;
    for(int j=0;j<N;j++){
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    }
    System.out.println(sum);
    
  } main {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int v[] = new int[N];
    
    for(int i=0;i<N;i++){
      v[i] = sc.nextInt();
    }
    
    Arrays.sort(v);
    double sum = 0;
    for(int j=0;j<N;j++){
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    }
    System.out.println(sum);
    
  } 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 i=0;i<N;i++){
      v[i] = sc.nextInt();
    } int i=0; int i=0; i 0 i<N i N i++ i++ i {
      v[i] = sc.nextInt();
    } {
      v[i] = sc.nextInt();
    } v[i] = sc.nextInt() v[i] v i sc.nextInt() sc.nextInt sc Arrays.sort(v) Arrays.sort Arrays v double sum = 0; sum 0 for(int j=0;j<N;j++){
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    } int j=0; int j=0; j 0 j<N j N j++ j++ j {
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    } {
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    } if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      } j==0 j 0 {
       sum = v[j];
      } sum = v[j] sum v[j] v j {
       sum = (sum+v[j])/2.0;
      } sum = (sum+v[j])/2.0 sum (sum+v[j])/2.0 (sum+v[j]) sum v[j] v j 2.0 System.out.println(sum) System.out.println System.out System System.out sum String[] args args
import java.util.Scanner;
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 i=0;i<N;i++){
      v[i] = sc.nextInt();
    }
    
    Arrays.sort(v);
    double sum = 0;
    for(int j=0;j<N;j++){
      if(j==0){
       sum = v[j];
      }else{
       sum = (sum+v[j])/2.0;
      }
    }
    System.out.println(sum);
    
  }
}