#include<fstream>
#include<deque>
#include<iomanip>
using namespace std;

int n,l,u,i;
int c[30002],t[30002];
deque <int> dq;
double s;

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

double raport(int i,int j)
{
    return (1.0*(c[i]-c[j]))/(1.0*(t[i]-t[j]));
}

int main()
{
    f>>n>>l>>u;

    for(i=1;i<=n;i++)
    {
        f>>c[i];
        c[i]+=c[i-1];
    }
    for(i=1;i<=n;i++)
    {
        f>>t[i];
        t[i]+=t[i-1];
    }

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

        if (!dq.empty() && dq.front() == i - u - 1) 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);

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

    g<<fixed<<setprecision(3)<<s;

    f.close();
    g.close();
    return 0;
}