# include <fstream>
# define DIM 30003
using namespace std;
int n, l, u, C[DIM], T[DIM];
double sol;

void read ()
{
	ifstream fin ("secv3.in");
	fin>>n>>l>>u;
	int x;
	for (int i=1;i<=n;i++)
	{
		fin>>x;
		C[i]=x*100+C[i-1];
	}
	for (int i=1;i<=n;++i)
	{
		fin>>x;
		T[i]=T[i-1]+x*100;
	}
}

void fct (int L)
{
	for(int i=L;i<=n;++i)
		if ((C[i]-C[i-L])/(double)(T[i]-T[i-L])>sol)
			sol=(C[i]-C[i-L])/(double)(T[i]-T[i-L]);
}

int main ()
{
	read ();
	for(int i=l;i<=u;++i)
		fct(i);
	freopen ("secv3.out", "w", stdout);
	printf("%.2lf", sol);
	return 0;
}