#include <iostream>
#include <stdlib.h>
using namespace std;

int main(void)
{
	int data_num;
	cin >> data_num;
	
	int *data_array;
	data_array = (int *)malloc(data_num);
	
	for(int i=0; i<data_num; i++)
		cin >> data_array[i];
	
	for(int i=0; i<data_num; i++)
	{
		bool swapped = false;
		for(int j=0; j<data_num-i-1; j++)
		{
			if(data_array[j]>data_array[j+1])
			{
				swap(data_array[j], data_array[j+1]);
				swapped = true;
			}
		}
		if(!swapped)
			break;
	}
	
	double median;
	if(data_num%2==1)
	{
		median = data_array[data_num/2];
	}
	else
	{
		median = (double)((double)data_array[data_num/2-1] + (double)data_array[data_num/2] )/2;
	}
	
	cout << median;
}