#include<fstream.h>
#include<stdio.h>

long c[30000], t[30000], n, l, u;
float maxim;

void citire()
{
  long i;
  ifstream in("secv3.in");
  in>>n;
  in>>l;
  in>>u;
  for (i=1; i<=n; i++)
    in>>c[i];
  for (i=1; i<=n; i++)
    in>>t[i];
}

float fractie(long a, long b)
{
  long sumac=0, sumat=0, i;
  float fr;
  for (i=a; i<=b; i++)
    {
      sumac+=c[i];
      sumat+=t[i];
    }
  fr=(float)sumac/sumat;
  return fr;
}

void calcul()
{

  long i, j;
  float max;
  for (i=1; i<=n-l+1; i++)
    for (j=i+l-1; j<=i+u-1 && j<=n; j++)
      {
	max=fractie(i,j);
	if (max>maxim) maxim=max;
      }
/*  ofstream out("secv3.out");
  out<<maxim;
  out.close(); */
  FILE *out=fopen("secv3.out","w");
  fprintf(out,"%.2f",maxim);
  fclose(out);
}


int main()
{
  citire();
  calcul();
  return 0;
}