#include <bits/stdc++.h>

using namespace std;
ifstream in("secv3.in");
ofstream out("secv3.out");
int n, l, u;
double long sc[30005], st[30005], x, k, Max=0;
deque<pair<double long,int>> q;
int main()
{
    in>>n>>l>>u;
    for(int i = 1; i <= n; i++)
    {
        in>>x;
        sc[i] = sc[i - 1] + x;
    }
    for(int i = 1; i <= n; i++)
    {
        in>>x;
        st[i] = st[i - 1] + x;
    }

    for(int i = 1;i <= n - l + 1; i++)
    {
        if(!q.empty() && q.front().second < i - u + l) q.pop_front();
        while(!q.empty()&& sc[i] - st[i] < q.back().first) q.pop_back();
        q.push_back({sc[i] - st[i],i});
        if((sc[i + l]-sc[q.front().second]) / (st[i + l]-st[q.front().second]) > Max)
            Max=(sc[i + l]-sc[q.front().second]) / (st[i + l]-st[q.front().second]);
    }
    out<<fixed<<setprecision(2)<<Max;
    return 0;
}