#include <fstream>
#include <iomanip>

using namespace std;

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

int x, s[30005], t[30005], i, j, n, l, u;
int fr, bk, dq[30005];
double maxim;

int main() {
    f >> n >> l >> u;
    for (i = 1; i <= n; i++) {
        f >> x;
        s[i] = s[i-1]+x;
    }
    for (i = 1; i <= n; i++) {
        f >> x;
        t[i] = t[i-1]+x;
    }
    //s //
    fr = 1, bk  =0;
    for (i = 1; i <= n; i++) {
        for (j = max(1, i-u+1); j <= i-l+1; j++)
            maxim = max(maxim, (double)((double)(s[i] - s[j-1])/((double)t[i]-t[j-1])));
    }
    g << fixed << setprecision(2) << maxim;
    return 0;
}