#include <bits/stdc++.h>
using namespace std;
ifstream in("secv3.in");
ofstream out("secv3.out");
const int N = 30005;
double s[N],t[N];
int main()
{
    int n,l,u;
    in >> n >> l >> u;
    for (int i = 1; i<=n; i++)
    {
        double x;
        in >> x;
        s[i] = s[i-1]+x;
    }
    for (int i = 1; i<=n; i++)
    {
        double x;
        in >> x;
        t[i] = t[i-1]+x;
    }
    double Max = s[l]/t[l];
    int j = 1;
    for (int i = l+1; i<=n; i++)
    {
        if (i-l == u)
            j++;
        double s1 = (s[i]-s[j-1])/(t[i]-t[j-1]), s2 = (s[i]-s[i-l])/(t[i]-t[i-l]);
        if (s2>s1)
            j = i-l+1;
        Max = max(Max,max(s1,s2));
    }
    out << Max;
}