#include <iostream>
#include<fstream>
#include<iomanip>
using namespace std;
ifstream f("secv3.in");
ofstream g("secv3.out");
int n,u,v,s[30001],c[30001],len,i,j,x;
double mx,val,s1,c1;
int main()
{
    f>>n>>u>>v;
    for(i=1;i<=n;i++)
    {
        f>>x;
        s[i]=s[i-1]+x;
    }
    for(i=1;i<=n;i++)
    {
        f>>x;
        c[i]=c[i-1]+x;
    }
    for(len=u;len<=v;len++)
        for(i=1;i+len-1<=n;i++)
    {
        j=i+len-1;
        s1=s[j]-s[i-1];
        c1=c[j]-c[i-1];
        val=s1/c1;
        mx=max(mx,val);
    }
    g<<setprecision(5)<<fixed<<mx;
}