#include <bits/stdc++.h>

using namespace std;

const int MAXN = 3e4 + 5;

int n, l, u;
int c[MAXN], t[MAXN];

deque <int> q;

double maxi(double a, double b)  {
    if(a < b)
        return b;
    return a;
}

int main()  {
    freopen("secv3.in", "r", stdin);
    freopen("secv3.out", "w", stdout);
    cin >> n >> l >> u;
    for(int i = 1;i <= n;i++)
        cin >> c[i], c[i] += c[i - 1];
    for(int i = 1;i <= n;i++)
        cin >> t[i], t[i] += t[i - 1];
    double ans = 1.0 * c[l] / t[l];
    for(int i = l;i <= n;i++)  {
        while(q.size() && q.front() <= i - u)
              q.pop_front();
        while(q.size() && 1LL * (c[i] - c[q.back() - 1]) * (t[i] - t[i - l]) < 1LL * (c[i] - c[i - l]) * (t[i] - t[q.back() - 1]))
              q.pop_back();
        q.push_back(i - l + 1);
        if(ans < 1.0 * (c[i] - c[q.front() - 1]) / (t[i] - t[q.front() - 1]))
            ans = 1.0 * (c[i] - c[q.front() - 1]) / (t[i] - t[q.front() - 1]);
    }
    cout << setprecision(2) << fixed << ans;
    return 0;
}