#include <iostream>

#include <array>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>

#include <string>
#include <sstream>

#include <memory>
#include <cassert>

#include <functional>

using namespace std;

const int MOD = 1000000007;

typedef unsigned long long ull;

int main()
{
	int N;
	cin >> N;

	vector<int> a(N);
	for (int i = 0; i < N; ++i) {
		cin >> a[i];
	}

	sort(a.begin(), a.end());

	if (N % 2 != 0) {
		cout << a[N / 2] << endl;
	} else {
		cout << (a[N / 2 - 1] + a[N / 2]) / 2.0 << endl;
	}
}