#include <iostream>
#include <algorithm>
using namespace std;
 
int main(){
	int N;
	cin >> N;
	int A[N];
	for(int i = 0; i < N; i++){
		cin >> A[i];
	}
	sort(A, A + N);
	if(N % 2 == 1){
		cout << A[N / 2] << endl;
	}else{
		cout << (A[N / 2 - 1] + A[N / 2]) / 2.0 << endl;
	}
}