import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Arrays;

public class Main {
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(in.readLine());
    double[] v = new double[n];
    String[] str = in.readLine().split(" ");
    for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    }
    Arrays.sort(v);
    for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    }
    System.out.println(v[n-1]);
  }
} import java.io.BufferedReader; BufferedReader java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.IOException; IOException java.io import java.util.Arrays; Arrays java.util public class Main {
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(in.readLine());
    double[] v = new double[n];
    String[] str = in.readLine().split(" ");
    for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    }
    Arrays.sort(v);
    for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    }
    System.out.println(v[n-1]);
  }
} Main public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(in.readLine());
    double[] v = new double[n];
    String[] str = in.readLine().split(" ");
    for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    }
    Arrays.sort(v);
    for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    }
    System.out.println(v[n-1]);
  } main {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(in.readLine());
    double[] v = new double[n];
    String[] str = in.readLine().split(" ");
    for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    }
    Arrays.sort(v);
    for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    }
    System.out.println(v[n-1]);
  } BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); in new BufferedReader(new InputStreamReader(System.in)) int n = Integer.parseInt(in.readLine()); n Integer.parseInt(in.readLine()) Integer.parseInt Integer in.readLine() in.readLine in double[] v = new double[n]; v new double[n] n String[] str = in.readLine().split(" "); str in.readLine().split(" ") in.readLine().split in.readLine() in.readLine in " " for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    } int i=0; int i=0; i 0 i<n i n i++ i++ i {
      v[i] = Integer.parseInt(str[i]);
    } {
      v[i] = Integer.parseInt(str[i]);
    } v[i] = Integer.parseInt(str[i]) v[i] v i Integer.parseInt(str[i]) Integer.parseInt Integer str[i] str i Arrays.sort(v) Arrays.sort Arrays v for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    } int i=0; int i=0; i 0 i<n-1 i n-1 n 1 i++ i++ i {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    } {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    } v[i+1] = (v[i]+v[i+1])/2.00000 v[i+1] v i+1 i 1 (v[i]+v[i+1])/2.00000 (v[i]+v[i+1]) v[i] v i v[i+1] v i+1 i 1 2.00000 System.out.println(v[n-1]) System.out.println System.out System System.out v[n-1] v n-1 n 1 String[] args args public class Main {
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(in.readLine());
    double[] v = new double[n];
    String[] str = in.readLine().split(" ");
    for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    }
    Arrays.sort(v);
    for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    }
    System.out.println(v[n-1]);
  }
} public class Main {
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(in.readLine());
    double[] v = new double[n];
    String[] str = in.readLine().split(" ");
    for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    }
    Arrays.sort(v);
    for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    }
    System.out.println(v[n-1]);
  }
} Main
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Arrays;

public class Main {
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    int n = Integer.parseInt(in.readLine());
    double[] v = new double[n];
    String[] str = in.readLine().split(" ");
    for(int i=0; i<n; i++) {
      v[i] = Integer.parseInt(str[i]);
    }
    Arrays.sort(v);
    for(int i=0; i<n-1; i++) {
      v[i+1] = (v[i]+v[i+1])/2.00000;
    }
    System.out.println(v[n-1]);
  }
}