#include <fstream>
#include <deque>

using namespace std;

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

const int N = 30002;

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

void solve() {
    deque <int> dq;

    for (int i = 1; i <= n; i++) {

        if (!dq.empty() && dq.front() == i - u) dq.pop_front();

        while (!dq.empty() && 1.0 * (v[i].first - v[dq.back()].first) / (v[i].second - v[dq.back()].second) <= 1.0 * (v[i].first - v[i - l].first) / (v[i].second - v[i - l].second)) dq.pop_back();
        dq.push_back(i - l);

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

int main()
{
    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;
    }
    in.close();

    solve();

    out << s;
    out.close();
}