#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<ll> vll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<vector<ll>> vvll;
const ll inf = 1e16;
const ll md = 1000000007;

int main() {
  int n;
  cin>>n;
  vi a(n);
  rep(i,n) cin>>a[i];
  sort(a.begin(),a.end());
  if(n&1) cout<<a[n/2]<<endl;
  else cout<<((float)a[n/2]+a[n/2-1])/2<<endl;
  return 0;
}