#include <stdio.h>
#define N 30001
int cost[N];
int timp[N];
int main ()
{freopen("secv3.in","r",stdin);
 freopen("secv3.out","w",stdout);
 int n,l,u,i,j,k,sc,st;
 float max=0,t;
 scanf("%d %d %d",&n,&l,&u);
 
 for (i=0;i<n;i++)
 {scanf("%d",&cost[i]);
 }
 
 for (i=0;i<n;i++)
 {scanf("%d",&timp[i]);
 }
 
 for (i=0;i<n;i++)
 {for (j=i+l;j<=i+u;j++)
  {sc=0;st=0;
   for (k=i;k<=j;k++)
   {st+=timp[k];
   }
   for (k=i;k<=j;k++)
   {sc+=cost[k];
   }
   if((t=(float)sc/st)>max)
   {max=t;
   }
  }
 }

 printf("%f",max);
 return 0;
}