#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 == 0){
    cout << (double) (A[N / 2 - 1] + A[N / 2]) / 2 << endl;
  } else {
    cout << A[N / 2] << endl;
  }
}