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