#include<iostream.h>
#include<stdio.h>
 FILE *f=fopen("secv3.in","r"),*g=fopen("secv3.out","w");
  int main()
{
 long n,l,u,a[30001],b[30001],j,i,s1,s2;
 float x,max=0;
  fscanf(f,"%ld %ld %ld\n",&n,&l,&u);
a[0]=0;
b[0]=0;
for(i=1;i<=n;i++)
 {
 fscanf(f,"%ld ",&a[i]);
  a[i]=a[i]+a[i-1];
}
for(i=1;i<=n;i++)
 {
 fscanf(f,"%ld ",&b[i]);
  b[i]=b[i]+b[i-1];
 if(i>=l)
{
  for(j=i-l;j>i-u&&j>=1;j--)
{
 s1=a[i]-a[j];
 s2=b[i]-b[j];
 x=s1/(float)s2;
if(x>max) max=x;
}
 }
  }
fprintf(g,"%f\n",max);
 return 0;
}