# include <iostream>
# include <algorithm>
# include <vector>
# include <string>
# include <set>
# include <map>
# include <cmath>
# include <iomanip>
# include <functional>
# include <utility>
# include <stack>
# include <queue>
# include <list>
using namespace std;
using LL = long long;
constexpr long long MOD = 1000000000 + 7;
constexpr long long INF = 1000000000;
const double PI = acos(-1);

int main() {
	int n;
	int a;
	vector<double> v;
	cin >> n;
	double ans;
	for (int i = 0; i < n; i++) {
		cin >> a;
		v.emplace_back(a);
	}
	sort(v.begin(), v.end());
	if (n % 2 == 0) {
		ans = (v[n / 2] + v[n / 2 - 1]) / 2;
	}
	else {
		ans = v[n / 2];
	}
	cout << ans << endl;
}