#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for (int i = 0; i < n; i++)
typedef long long ll;
// Welcome to my source code!

int main() {
    int n;
    cin >> n;
    int A[n];
    REP(i,n) cin >> A[i];
    sort(A, A+n);
    if (n%2) {
        cout << A[n/2] << endl;
    } else {
        cout << (A[n/2-1]+A[n/2])/2.0 << endl;
    }
}