#include<bits/stdc++.h>
using namespace std;
ifstream f("secv3.in");
ofstream g("secv3.out");
int n,l,r,nr;
double rmax,r2;
double v[30001],v2[30001];
int main()
{
    f>>n>>l>>r;
    for(int i=1;i<=n;++i)
        f>>nr,v[i]=nr+v[i-1];
    for(int i=1;i<=n;++i)
        f>>nr,v2[i]=nr+v2[i-1];
    for(int i=l;i<=n-l+1;++i){
        int sf=min(n,i+min(r-1,l+1000));
        for(int j=i+l-1;j<=sf;++j)
            if((v[j]-v[i-1])>rmax*(v2[j]-v2[i-1]))
                rmax=(v[j]-v[i-1])/(v2[j]-v2[i-1]);
    }
    g<<fixed<<setprecision(2)<<rmax<<'\n';
    return 0;
}