#include <iostream>

#define SWAP(type, a, b) { type work = a; a = b; b = work; }

using namespace std;

void my_qsort(int *array, size_t size);
void qsort_rec(int *array, int begin, int end);
inline int select_pivot(const int *array, int begin, int end);

int main() {
    int num;
    int input[1000];
    int ans = 0;

    cin >> num;
    for (int i = 0; i < num; i++){
        cin >> input[i];
        //cout << input[i] << "\n";
    }
    my_qsort(input, num);

    if (num % 2 != 0) {
        cout << input[num / 2] << "\n";
    }
    else {
        //cout << input[num / 2] << " " << input[(num / 2) + 1] << "\n";
        cout << (double)((input[(num / 2) - 1] + input[(num / 2)]) / 2.0) << "\n";
    }
    


    return 0;
}

void my_qsort(int *array, size_t size)
{
    qsort_rec(array, 0, (int)(size - 1));
}
void qsort_rec(int *array, int begin, int end)
{
    int pivot = select_pivot(array, begin, end);
    int i = begin;
    int j = end;
    
    while(1) {
        while(array[i] < pivot) { ++i; }
        while(array[j] > pivot) { --j; }
    
        if (i >= j) { break; }
        SWAP(int, array[i], array[j]);
        i++;
        j--;
    }

    if (i - begin >= 2) {
        qsort_rec(array, begin, i-1);
    }
    
    if (end - j >= 2) {
        qsort_rec(array, j + 1, end);
    }
}
inline int select_pivot(const int *array, int begin, int end)
{
    return array[(begin + end) / 2];
}