#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>
using namespace std;
int main()
{
int n;cin >> n;
vector<int> v(n);
for(int i = 0; i < n;i++){
cin >> v[i];
}
sort(v.begin(), v.end());
if(n % 2 == 1){
cout << v[(n-1)/2] << endl;
} else {
cout << fixed << setprecision(1) << (v[(n-2)/2]+v[n/2])*1.0/2 << endl;
}
return 0;
}