#include<fstream.h>
int a[30000],b[30000],N,U,L;
double S1,S2;
void citire(){
ifstream fin("secv3.in");
fin>>N>>L>>U;
for (int i=0;i<N;i++)
  fin>>a[i];
for (int j=0;j<N;j++)
    fin>>b[j];
fin.close();
}
void  cost (int y,int n){
S1=0;
S2=0;
     for (int i=y;i<n;i++){
	  S1+=a[i];
	  S2+=b[i];}
}
double maxim (){
double max=0,S;
cost(0,L);
double S11=S1,S22=S2;
   for (int i=0;i<N-L+1;i++){
      for (int j=i+L;j<=i+U;j++){
	 S=S11/S22;
	if (S>max)
	   max=S;
	   S11+=a[j];
	   S22+=b[j];}
	if (S>max)
	   max=S;
	S1=S1-a[i]+a[i+L];
	S2=S2-b[i]+b[i+L];
	S11=S1;
	S22=S2;}
return max*100;
}
int main(){
citire();
ofstream fout("secv3.out");
long n=maxim();
fout<<n/100<<"."<<n%100;
fout<<"\n";
fout.close();
return 0;
}