import java.util.*;
 
public 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 value = v[0];
    for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    }
    System.out.println(value);
  }
} import java.util.*; util.* java public 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 value = v[0];
    for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    }
    System.out.println(value);
  }
} 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 value = v[0];
    for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    }
    System.out.println(value);
  } 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 value = v[0];
    for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    }
    System.out.println(value);
  } 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 value = v[0]; value v[0] v 0 for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    } int i=1; int i=1; i 1 i<N i N i++ i++ i {
      value = (value + v[i])/2;
    } {
      value = (value + v[i])/2;
    } value = (value + v[i])/2 value (value + v[i])/2 (value + v[i]) value v[i] v i 2 System.out.println(value) System.out.println System.out System System.out value String[] args args public 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 value = v[0];
    for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    }
    System.out.println(value);
  }
} public 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 value = v[0];
    for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    }
    System.out.println(value);
  }
} Main
import java.util.*;
 
public 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 value = v[0];
    for(int i=1; i<N; i++){
      value = (value + v[i])/2;
    }
    System.out.println(value);
  }
}