#include <bits/stdc++.h>

using namespace std;

int c[30005], t[30005];
int main()
{
    ifstream cin("secv3.in");
    ofstream cout("secv3.out");

    int n, mn, mx;
    cin >> n >> mn >> mx;
    for(int i=1; i<=n; i++)
    {
        cin >> c[i];
    }
    for(int i=1; i<=n; i++)
    {
        cin >> t[i];
    }
    for(int i=2; i<=n; i++)
    {
        c[i] = c[i - 1] + c[i];
        t[i] = t[i - 1] + t[i];
    }
    double sol = 1.0 * c[mn] / (1.0 * t[mn]);
    int j = 1;
    for(int i = mn + 1; i <= n; i++)
    {
        if(i - j == mx - 1)
            j++;
        double ans1=1.0 * (c[i] - c[j - 1]) / (1.0 * (t[i] - t[j - 1]));
        double ans2=1.0 * (c[i] - c[i - mn]) / (1.0 * (t[i] - t[i - mn]));
        if(ans2>ans1)
        {
            j = i - mn + 1;
        }
        sol = max(sol, max(ans1, ans2));
    }
    cout << fixed << setprecision(10) << sol;
    return 0;
}