#include<stdio.h>
int c[ 30010 ],t[ 30010 ],n,l,j,i,u,p,sc,st;

float maxim;

int main(){
freopen("secv3.in","r",stdin);
freopen("secv3.out","w",stdout);

scanf("%d %d %d",&n,&l,&u);

for(i = 1; i <= n; i++){
	scanf("%d",&c[i]);
	c[i] += c[i-1];}
for(i = 1; i <= n ; i++){
	scanf("%d",&t[i]);
	t[i] += t[i-1];}

	
for(i = l;i <= n; i++)
	for(j = i-l;j >= 0 && j >= i-u;j--)
		if(float(c[i] - c[j])/float(t[i] - t[j] ) > maxim)
			maxim = float(c[i] - c[j])/float(t[i] - t[j]);
	
printf("%f",maxim);
return 0;}