#include <fstream>
#include <deque>
#include <iomanip>

using namespace std;

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

const double eps = 1e-2;

int N, U, L;
int cost[30005], timp[30005];
double sol, sp[30005];
deque<int> DQ;

bool solve(double x)
{
    DQ.clear();

    sp[1] = cost[1] - x * timp[1];
    for (int i = 2; i <= N; ++i)
        sp[i] = sp[i - 1] + cost[i] - x * timp[i];

    for (int i = L; i <= N; ++i)
    {
        while (!DQ.empty() && sp[DQ.back() - 1] >= sp[i - L + 1]) // minimul
            DQ.pop_back();
        DQ.push_back(i - L + 1);

        while (DQ.front() < i - U + 1)
            DQ.pop_front();

        if (sp[i] - sp[DQ.front() - 1] >= eps)
            return true;
    }

    return false;
}

int main()
{
    fin >> N >> L >> U;
    for (int i = 1; i <= N; ++i)
        fin >> cost[i];
    for (int i = 1; i <= N; ++i)
        fin >> timp[i];

    double lt = 0.0, rt = 30000000.0;
    while (rt - lt > eps)
    {
        double mid = (lt + rt) / 2.0;

        if (solve(mid))
        {
            lt = mid;
            sol = mid;
        }
        else
            rt = mid;
    }

    fout << fixed << setprecision(2) << sol << '\n';

    fin.close();
    fout.close();
    return 0;
}