#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; //define #define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl; #define dump(x) cerr << #x << " = " << (x) << endl; #define INF (INT_MAX/2) #define PI (2*acos(0.0)) #define EPS (1e-8) #define REP(i,a,b) for(int i=(a); i<(b);++i) #define rep(i,n) REP(i,0,n) typedef long long ll; typedef unsigned long long ull; typedef pair pii; typedef pair pll; typedef vector vint; typedef vector > vvint; typedef vector vll; typedef vector > vvll; int dx[8] = {0, 1, 0, -1, 1, -1, 1, -1}; int dy[8] = {1, 0, -1, 0, 1, -1, -1, 1}; int main(void){ ios_base::sync_with_stdio(0); int n; cin >> n; vector v(n); for(int i = 0; i < n; i++) cin >> v[i]; sort(v.begin(), v.end()); if(v.size() % 2 == 0){ int l = v.size() / 2 - 1, r = v.size() / 2; cout << (v[l] + v[r]) / 2.0 << endl; }else{ cout << v[v.size()/2] << endl; } return 0; }