#include <iostream>
#include <fstream>
#define For(i,a,b) for (int i=(a);i<=(b);++i)
#include <iomanip>
using namespace std;
int n,l,u;
double mx,cost[30004],timp[30004],costSuma[30004],timpSuma[30004],sf;
int main()
{
    ifstream in("secv3.in");
    ofstream out("secv3.out");
    in >>n>>l>>u;
    For(i,1,n)
    {
        in >>cost[i];
        costSuma[i]=costSuma[i-1]+cost[i];
    }
    For(i,1,n)
    {
        in >>timp[i];
        timpSuma[i]=timpSuma[i-1]+timp[i];
    }
    For(i,1,n-u+1)
    {
        for (int j=i+u-1,sf=min(n,i+min(l-1,u+1000));j<=sf;++j)
        {
            if (costSuma[j]-costSuma[i-1]>mx*(timpSuma[j]-timpSuma[i-1]));
            {
                mx=(costSuma[j]-costSuma[i-1])/(timpSuma[j]-timpSuma[i-1]);
            }
        }
    }
    out <<setprecision(2)<<mx;
    return 0;
}