#include <fstream>
#include <deque>

using namespace std;

ifstream in("secv3.in");
ofstream out("secv3.out");

const int N = 30000;

int n, l, u;
pair <double, double> v[N];
deque <int> dq;

int main()
{
    double m;
    in >> n >> l >> u;
    for (int i = 1; i <= n; i++) {in >> v[i].first; v[i].first += v[i - 1].first;}
    for (int i = 1; i <= n; i++) {in >> v[i].second; v[i].second += v[i - 1].second;}
    for (int i = 1; i <= n; i++) {
        if (!dq.empty() && dq.front() == i - u - 1) dq.pop_front();

        while (!dq.empty() && v[dq.back()].first <= v[i - 1].first) dq.pop_back();
        dq.push_back(i - 1);

        if (i >= l) m = max(m, 1.0 * (v[i].first - v[dq.front()].first) / (v[i].second - v[dq.front()].second));
    }
    out << m;
}