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

using namespace std;

int main()
{
	float result;
	int n, i;
	cin >> n;
	vector<__int64> a(n);

	for ( i = 0; i < n; ++i )
	{
		scanf("%I64d",&a[i]);
	}

	stable_sort( a.begin (), a.end () );

	if ( n % 2 )
		result = a[(n - 1) / 2];
	else 
		result = (a[(n / 2) - 1] + a[n / 2]) / 2.0;

	printf("%.1f\n", result);

	return 0;
}