#include <stdio.h>
#include <algorithm>
#include <deque>
using namespace std;
using ll = long long;

int main() {
	int n, a[1000];
	scanf("%d", &n);
	for (int i = 0; i < n; i++)
		scanf("%d", a + i);
	sort(a, a + n);

	if (n & 1)
		printf("%d\n", a[n / 2]);
	else {
		double sum = a[n / 2] + a[n / 2 - 1];
		printf("%.1lf", sum / 2.);
	}
}