#include <iostream>
#include <cstdio>
using namespace std;

int main() {
    int a[100] = {0}, n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    double median;
    if (n % 2 == 1) {
        median = a[(n - 1) / 2];
    } else {
        median = (a[n / 2 - 1] + a[n / 2]) / 2.0;
    }
    printf("%.1f\n", median);
    return 0;
}
/**************************************************************
	Problem: 1233
	User: panyuchen
	Language: C++
	Result: Wrong Answer
****************************************************************/