#include <fstream>
#include <deque>
#include <algorithm>

using namespace std;

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

const int Max = 30007, sonsuz = 10000000;
int n, l, u, c[Max], t[Max];

double sum2(double x)
{
    double toplam[Max], zaman[Max];
    toplam[0] = 0;
    deque<int> q;
    double cevap = -30000000;
    for(int i = 1; i <= n; ++i)
    {
        zaman[i] = c[i] - (x * t[i]);
        toplam[i] = toplam[i - 1] + zaman[i];
    }
    for(int i = 1; i <= n; ++i)
    {
        while(!q.empty() && toplam[i - l] <= toplam[q.back()])
            q.pop_back();
        q.push_back(i - l);
        if(q.front() < i - u)
            q.pop_front();
        cevap = max(cevap, toplam[i] - toplam[q.front()]);
    }

    return cevap;
}

double ara()
{
    double st = 0, dr = 30007;
    for(int i = 1; i <= 40; ++i)
    {
        double mid  = (st + dr) / 2;
        if(sum2(mid) > 0)
            st = mid;
        else
            dr = mid;
    }

    return dr;
}

int main()
{
    in >> n >> l >> u;
    for(int i = 1; i <= n; ++i)
        in >> c[i];
    for(int i = 1; i <= n; ++i)
        in >> t[i];

    out << ara();
}