import java.util.Scanner;
import java.lang.Math;

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

         int N = sc.nextInt();
         int[] A = new int[N];
         for(int i=0; i<N; i++){
             A[i] = sc.nextInt();
         }
         
         for(int j=0; j<A.length-1; j++){
             for(int k=N-1; k>j; k--){
                 if(A[k] < A[k-1]){
                     int temp = A[k];
                     A[k] = A[k-1];
                     A[k-1] = temp;
                 }
             }
         }
         

         if(N%2==0){
             double center = (double)(A[N/2] + A[(N/2)-1]) / 2;
             System.out.println(center);
         }else{
             int center = A[N/2];
             System.out.println(center);
         }
   
     }
 }