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

using namespace std;

int 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;
		return 0;
	}
	cout << float ( A.at( N/2-1 ) + A.at( N /2 ) )/ 2   << endl;

		
	return 0;
}