#include<iostream> #include<cstdio> #include<cstring> #include<string> #include<cctype> #include<cstdlib> #include<algorithm> #include<bitset> #include<vector> #include<list> #include<deque> #include<queue> #include<map> #include<set> #include<stack> #include<cmath> #include<sstream> #include<fstream> #include<iomanip> #include<ctime> #include<complex> #include<functional> #include<climits> #include<cassert> #include<iterator> using namespace std; int n; vector<int> v; int main(){ scanf("%d", &n); for (int i = 0; i < n; i++){ int a; scanf("%d", &a); v.push_back(a); } sort(v.begin(), v.end()); if (n % 2){ int k = v[n / 2]; cout << k << endl; } else{ double r = v[n / 2] + v[n / 2 - 1]; r /= 2.0; printf("%.6f\n", r); } return 0; }