#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;
ifstream f("secv3.in");
ofstream g("secv3.out");
int a[100], b[100];
class sirDeNumere{
public:
    int minimZ;
    int maximZ;
    double maxim;
    double sir(int i) {
        int intermediar = minimZ, sum1=0, sum2=0, k=0, alfa;
        alfa = maximZ-minimZ+1;
        double abc[alfa], mavarnaxim = 0;
        while (intermediar <= maximZ){
            for (int x=0; x<intermediar; x++) {
                sum1+=a[i-x];
                sum2+=b[i-x];
            }
            abc[++k] = (double)sum1/sum2;
            intermediar++;
        }
        for (int x=1; x<=k; x++) {
            if (abc[x] > mavarnaxim) mavarnaxim = abc[x];
        }
        return (double)mavarnaxim;
    }
};
int main()
{
    int n, l, m, i;
    double maximz = 0;
    sirDeNumere x;
    f>>n;
    f>>l;
    f>>m;
    x.minimZ = l;
    x.maximZ = m;
    for (i=1; i<=n; i++)
        f>>a[i];
    for (i=1; i<=n; i++)
        f>>b[i];
    for (i=x.minimZ; i<=n; i++){
        if (x.sir(i) > maximz)
            {
                maximz = x.sir(i);
            }
    }
    g<<setprecision (2) << fixed <<maximz;
    return 0;
}