#include <bits/stdc++.h>
#define int long long
using namespace std;
using Graph = vector<vector<int>>;

signed main(){
  int N;
  cin >> N;
  
  vector<int> A(N);
  for( int i = 0; i < N; i++ ) cin >> A.at(i);
  sort(A.begin(), A.end());
  if( N%2 == 1 ) cout << A.at(N/2) << endl;
  else{
    double ans = (A.at(N/2)+A.at(N/2-1))/2.0;
    cout << ans << endl;
  }
  
}