#include <bits/stdc++.h>

using namespace std;

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

int n, l, u, a[30005], b[30005];

double s[30005];

double check(double val)
{
    s[0] = 0;
    for (int i = 1; i <= n; i++)
        s[i] = s[i - 1] + a[i] - val * b[i];

    deque<pair<double, int>>q;
    double Max = -INT_MAX;
    for (int i = l; i <= n; i++) {
        while (!q.empty() && s[i - l] < q.back().first)
            q.pop_back();

        q.push_back({s[i - l], i - l});

        if (!q.empty() && q.front().second < i - u)
            q.pop_front();

        Max = max(Max, s[i] - q.front().first);
    }
    return (Max >= 0);
}

double caut_bin()
{
    double i = 0., step = (1 << 20) * 1.;
    int cnt = 1;
    while (cnt <= 30) {
        //cout << check(i + step) << '\n';
        if (check(i + step))
            i += step;
        step /= 2;
        cnt++;
    }
    return i;
}

int main() {
    in >> n >> l >> u;
    for (int i = 1; i <= n; i++)
        in >> a[i];
    for (int i = 1; i <= n; i++)
        in >> b[i];

    double sol = caut_bin();
    out << fixed << setprecision(2) << sol;
    return 0;
}