#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
  int n;
  cin >> n;
  vector<int> vs( n );
  for( int i = 0; i < n; i++ ) {
	cin >> vs[ i ];
  }

  sort( vs.begin(), vs.end() );

  if ( n % 2 == 1 ) {
	cout << vs[ n / 2 ] << endl;
  } else {
	cout << ( vs[ n/2 ] + vs[n/2-1] ) / 2.0 << endl;
  }
}