#include <fstream>
#include <iomanip>

using namespace std;

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

const int nmax=30005;

int n,l,u;
double cost[nmax],timp[nmax];

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

    for(int i=1;i<=n;i++)
    {
        cin>>cost[i];
        cost[i]+=cost[i-1];
    }

    for(int j=1;j<=n;j++)
    {
        cin>>timp[j];
        timp[j]+=timp[j-1];
    }

    //1 2 3 4 5

    double ans=0.0;

    for(int i=l;i<=n;i++)
        for(int j=max(0,i-u);j<=i-l;j++)
            ans=max(ans,(cost[i]-cost[j])/(timp[i]-timp[j]));

    cout<<fixed<<setprecision(2)<<ans;


    return 0;
}