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