# include <stdio.h>
int a[30005],b[30005],n,k,s1,s2,i,j,l,u;
float s,smax;
int main ()
{
freopen ("secv3.in","r",stdin);
freopen ("secv3.out","w",stdout);
scanf ("%i%i%i",&n,&l,&u);
for (i=1;i<=n;i++)
scanf ("%i",&a[i]);
for (i=1;i<=n;i++)
scanf ("%i",&b[i]);
for (i=1;i<=n;i++)
{
s1=0;
s2=0;
for (j=i;j<=n;j++)
{
s1=s1+a[j];
s2=s2+b[j];
s=s1/(s2/1.0);
if (j-i+1>=l && j-i+1<=u)
if (smax<s)
{
smax=s;
}
if (j-i+1>u)
break;
}
}
printf ("%.2f",smax);
return 0;
}