#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) {
cout << A[N/2] << endl;
}
else {
cout << (double)(A[N/2] + A[N/2+1]) / 2 << endl;
}
return 0;
}