#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;
}