#include <fstream>
#include <iomanip>
using namespace std;
ifstream cin("secv3.in");
ofstream cout("secv3.out");
int L,U,N, c[30100], t[30100], sc[30100], f[30100], st[30100];
long double solprst()
{
    long double ans=0, may=0;
    for(int lg=L; lg<=U; ++lg)
        for(int inc=1; inc<=N-lg+1; ++inc)
        {
            may=sc[inc+lg-1]-sc[inc-1];
            may/=(st[inc+lg-1]-st[inc-1]);
            if(may>ans)
                ans=may;
        }
    return ans;
}

long double solok()
{

}

int main()
{
    cin>>N>>L>>U;
    for(int i=1; i<=N; ++i)
    {
        cin>>c[i];
        sc[i]=sc[i-1]+c[i];
    }

    for(int i=1; i<=N; ++i)
    {
        cin>>t[i];
        st[i]=st[i-1]+t[i];
        f[i]=c[i]/t[i];
    }

    long double ans=solprst();
    int ans1=ans*100;
    cout<<ans1/100<<'.';
    if(ans1%100<10)
        cout<<0;
    cout<<ans1%100<<'\n';
    return 0;
}