#include <bits/stdc++.h>
using namespace std;

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) cout << A[N/2] << endl;
	else cout << float(A[N/2-1] + A[N/2]) / 2.0 << endl;
	
	return 0;
}