#include <fstream>
#include <iomanip>

using namespace std;

ifstream f ("secv3.in");
ofstream g ("secv3.out");

int n, i, low, up, lg, x, st, dr;
double maxim, raport;
long long cost[30001], timp[30001];

int main()
{
   f >> n >> low >> up;
    for (i=1; i<=n; i++)
    {
        f >> x;
        cost[i] = cost[i-1] + x;
    }
    for (i=1; i<=n; i++)
    {
        f >> x;
        timp[i] = timp[i-1] + x;
    }
    lg = low;
    while (lg <= up)
    {
        st = 1;
        dr = lg - 1;
        while (dr <= n)
        {
            raport = (cost[dr] - cost[st-1]);
            raport /= (timp[dr] - timp[st-1]);
            if (raport > maxim)
                maxim = raport;
            st ++;
            dr ++;
        }
        lg ++;
    }
    g << fixed << setprecision(2) << maxim;
    return 0;
}