#include<stdio.h>
long int n,l,u,i,p,cit,c[30001],t[30001],cc,tc,cs,ts;
int main()
{
	FILE *f,*g;f=fopen("secv3.in","r");g=fopen("secv3.out","w");
	fscanf(f,"%ld%ld%ld",&n,&l,&u);
	for(i=1;i<=n;i++){fscanf(f,"%ld",&cit);c[i]=c[i-1]+cit;}
	for(i=1;i<=n;i++){fscanf(f,"%ld",&cit);t[i]=t[i-1]+cit;}
	u=(2*l<u)?2*l:u;cs=0;ts=1;
	for(p=l;p<=u;p++)
	 for(i=0;i<=n-p;i++)
	  if(ts*(c[i+p]-c[i])>cs*(t[i+p]-t[i]))
	   {cs=c[i+p]-c[i];ts=t[i+p]-tp[i];}
	fprintf(g,"%.3lf",(double)cs/(double)ts);
	fcloseall();
	return 0;
}