#include <bits/stdc++.h>
using namespace std;
int n,U,L,a[30005],b[30005];
deque<int>maxim;
deque<int>minim;
ifstream fin ("secv3.in");
ofstream fout("secv3.out");
void Citire()
{
    int i,x,y;
    fin>>n>>U>>L;
    for(i=1;i<=n;i++)
        fin>>a[i];
    for(i=1;i<=n;i++)
        fin>>b[i];
    for(i=1;i<=n;i++)
    {
        a[i]=a[i-1]+a[i];
        b[i]=b[i-1]+b[i];
    }
    fin.close();
}
void Rezolvare()
{
    int i,j,x,y;
    double sol=-10000000;
    for(i=1;i<=n;i++)
        for(j=i;j<=n;j++)
          if(j-i>=U and j-i<=L)
    {
        x=a[j]-a[i];
        y=b[j]-b[i];
        sol=max(sol,(double)x/y);
    }
    fout<<fixed<<setprecision(2)<<sol<<"\n";
}
int main()
{
    Citire();
    Rezolvare();
    return 0;
}