#include <fstream.h>
#include <iomanip.h>

double c[30100],t[30100];
long n,l,u,i,j;
double max,a;

int main(){
fstream f("secv3.in",ios::in);
fstream g("secv3.out",ios::out);
  f>>n>>l>>u;c[0]=0;t[0]=0;
  for (i=1;i<=n;i++) {f>>c[i]; c[i]+=c[i-1];}
  for (i=1;i<=n;i++) {f>>t[i]; t[i]+=t[i-1];}
  for (i=0;i<=n-u+1;i++)
    for (j=i+l;j<=i+u;j++){
      a=(c[j]-c[i])/(t[j]-t[i]);
      if (a>max) max=a;  
    }        
  for (i=n-u+2;i<=n-l+1;i++)
    for (j=i+l;j<=n;j++){
      a=(c[j]-c[i])/(t[j]-t[i]);
      if (a>max) max=a;  
    }            
  g<<setprecision(2)<<max;
f.close();g.close();
return 0;
}