#include <bits/stdc++.h>

using namespace std;

int main()
{
  int N, A[1000];
  cin >> N;
  for(int i = 0; i < N; i++) cin >> A[i];
  sort(A, A + N);
  if(N % 2 == 0) cout << (A[N / 2 - 1] + A[N / 2]) * .5 << endl;
  else cout << A[N / 2] << endl;
}