#include <iostream> #include <algorithm> #include <iomanip> #include <iterator> #include <numeric> using std::cin; using std::cout; const char endl = '\n'; const int N = 2e5 + 5; int n, a[N], s[N]; double ans; double calc(int pos, int len) { return static_cast<double>(s[n] - s[n - len] + s[pos] - s[pos - len - 1]) / (len * 2 + 1); } int solve(int x) { int l = 1, r = std::min(x - 1, n - x), res = 0; while (l <= r) { int mid = (l + r) >> 1; if (calc(x, mid - 1) <= calc(x, mid)) { res = mid; l = mid + 1; } else { r = mid - 1; } } return res; } int main() { std::ios::sync_with_stdio(false); cin.tie(nullptr); cin >> n; std::copy_n(std::istream_iterator<int>(cin), n, a + 1); std::sort(a + 1, a + 1 + n); std::partial_sum(a + 1, a + 1 + n, s + 1); for (int i = 2; i < n; i++) { ans = std::max(ans, calc(i, solve(i)) - a[i]); } cout << std::fixed << std::setprecision(5) << ans << endl; return 0; }