#include <cstdio>

using namespace std;

int c [30001];
int t [30001];

int main () {
    int n, l, r, i, j, k, s1, s2;
    double ans, g;

    freopen ("secv3.in", "r", stdin);
    freopen ("secv3.out", "w", stdout);

    scanf ("%d%d%d", &n, &l, &r);
    ans = 0;
    for (i = 1; i <= n; i ++) {
        scanf ("%d",&c [i]);
    }
    for (i = 1; i <= n; i ++)
        scanf ("%d", &t [i]);
    for (k = l; k <= r; k ++) {
        for (i = 1; i <= n; i ++) {
            s1 = s2 = 0;
            for (j = i; j <= i + k - 1; j ++) {
                s1 = s1 + c [j];
                s2 = s2 + t [j];
            }
        g = (double)s1 / s2;
        if (g > ans)
            ans = g;
        }
    }
    printf ("%.2lf", ans);
    return 0;
}