#include <stdio.h>
using namespace std;
#define nmax 30001
FILE *f=fopen("secv3.in","r");
FILE *g=fopen("secv3.out","w");
int n,u,l;
float C[nmax],T[nmax],C2[nmax],T2[nmax];
void read()
 {
 int i;
 fscanf(f,"%d %d %d",&n,&l,&u);
 for(i=1;i<=n;i++)
  fscanf(f,"%f",&C[i]);
 for(i=1;i<=n;i++)
  fscanf(f,"%f",&T[i]);
 for(i=1;i<=n;i++)
  {
  T2[i]=T2[i-1]+T[i];
  C2[i]=C2[i-1]+C[i];
  }
 }
void solve()
 {
 float sc,st,x;
 int j,i;
 x=0;
 for(j=l;j<=u;j++)
  for(i=j;i<=n;i++)
   {
   st=T2[i]-T2[i-l];
   sc=C2[i]-C2[i-l];
   if(sc/st>x)
    x=sc/st;
   }
 fprintf(g,"%.2f",x);
 }
int main()
 {
 read();
 solve();
 return 0;
 }