#include <cstdio>
#define fin  "secv3.in"
#define Nmax 30001
#define EPS 0.00001

int N,L,U,a[Nmax],b[Nmax];
double bst;

int main()
{
	int i,j,s1,s2;
	double sum;

	freopen(fin,"r",stdin);
	freopen("secv3.out","w",stdout);
	
	scanf("%d%d%d",&N,&L,&U);

	for (i=1;i<=N;++i)
		scanf("%d",&a[i]);
	for (i=1;i<=N;++i)
		scanf("%d",&b[i]);
	
	for (i=L;i<=N;++i)
	for (j=i,s1=0,s2=0;j>i-U;--j)
	{
		s1+=a[j];
		s2+=b[j];
		sum=(double)s1/(double)s2;
		if (j<=i-L+1 && sum-bst > EPS )
			bst=sum;
	}		
	
	printf("%.10lf\n",bst);

	return 0;
}