import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        List<Integer> list = new ArrayList<Integer>();
        
        for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        }
        
        Collections.sort(list);
        
        //System.out.println(list.get(0));
        
        double value = list.get(0);
        
        for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        }
        
        System.out.println(value);
        
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        List<Integer> list = new ArrayList<Integer>();
        
        for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        }
        
        Collections.sort(list);
        
        //System.out.println(list.get(0));
        
        double value = list.get(0);
        
        for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        }
        
        System.out.println(value);
        
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        List<Integer> list = new ArrayList<Integer>();
        
        for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        }
        
        Collections.sort(list);
        
        //System.out.println(list.get(0));
        
        double value = list.get(0);
        
        for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        }
        
        System.out.println(value);
        
    } main {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        List<Integer> list = new ArrayList<Integer>();
        
        for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        }
        
        Collections.sort(list);
        
        //System.out.println(list.get(0));
        
        double value = list.get(0);
        
        for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        }
        
        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 List<Integer> list = new ArrayList<Integer>(); list new ArrayList<Integer>() for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        } int i=0; int i=0; i 0 i<N i N i++ i++ i {
            list.add(sc.nextInt());
        } {
            list.add(sc.nextInt());
        } list.add(sc.nextInt()) list.add list sc.nextInt() sc.nextInt sc Collections.sort(list) Collections.sort Collections list double value = list.get(0); value list.get(0) list.get list 0 for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        } int i=1; int i=1; i 1 i<N i N i++ i++ i {
            value = (value + list.get(i))/2;
            //System.out.println(value);
        } {
            value = (value + list.get(i))/2;
            //System.out.println(value);
        } value = (value + list.get(i))/2 value (value + list.get(i))/2 (value + list.get(i)) value list.get(i) list.get list 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) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        List<Integer> list = new ArrayList<Integer>();
        
        for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        }
        
        Collections.sort(list);
        
        //System.out.println(list.get(0));
        
        double value = list.get(0);
        
        for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        }
        
        System.out.println(value);
        
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        List<Integer> list = new ArrayList<Integer>();
        
        for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        }
        
        Collections.sort(list);
        
        //System.out.println(list.get(0));
        
        double value = list.get(0);
        
        for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        }
        
        System.out.println(value);
        
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        
        List<Integer> list = new ArrayList<Integer>();
        
        for(int i=0;i<N;i++){
            list.add(sc.nextInt());
        }
        
        Collections.sort(list);
        
        //System.out.println(list.get(0));
        
        double value = list.get(0);
        
        for(int i=1;i<N;i++){
            value = (value + list.get(i))/2;
            //System.out.println(value);
        }
        
        System.out.println(value);
        
    }
}
