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

int main()
{
	int N;
	std::cin >> N;
	std::vector<double> A(N);
	for(int i=0;i<N;++i){
		std::cin >> A[i];
	}
	std::sort(A.begin(),A.end());
	if(N % 2 == 0){
		std::cout << (A[N/2-1] + A[N/2])/2 <<std::endl;
	}else{
		std::cout << A[N/2] << std::endl;
	}
	return 0;
}