import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Scanner;

class Yukicoder {
    static public void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int N = scanner.nextInt();
        if (N < 1 || N > 1000) System.exit(1);
        int[] A = new int[N];
        for (int i = 0; i < N; i++) {
            A[i] = scanner.nextInt();
            if (A[i] < -1000 || A[i] > 1000) System.exit(1);
        }

        for (int i = N; i > 1; i--) {
            heapSort(i, A);
            swap(A, 0, i-1);
        }

        float mid;
        if (N%2 == 1) mid = A[N/2];
        else mid = (((float) A[N / 2 - 1]) + A[N/2])/2;

        System.out.println(mid);
    }

    static public void heapSort (int leaf, int[] A) {
        int root = leaf/2-1;
        int tmp;
        for (int i = root; i >= 0; i--) {
            while ((root+1)*2 <= leaf) {
                if ((root+1)*2 == leaf) {
                    tmp = (root+1)*2 - 1;
                } else {
                    if (A[(root+1)*2 - 1] < A[(root+1)*2]) tmp = (root+1)*2;
                    else tmp = (root+1)*2 - 1;
                }
                if (A[root] < A[tmp]) {
                    swap(A, root, tmp);
                    root = tmp;
                } else break;
            }
            root = i - 1;
        }
    }

    static private void swap (int[] A, int a, int b){
        int tmp;
        tmp = A[a];
        A[a] = A[b];
        A[b] = tmp;
    }
}