#include <fstream>
#include <iomanip>
using namespace std;
 
int t[30001];
int c[30001];
 
int main()
{
    ifstream fin("secv3.in");
    ofstream fout("secv3.out");
 
    int N,L,U;
    fin >> N >> L >> U;
     
    for (int i = 1; i <= N; i++)
        fin >> c[i];
    for (int i = 1; i <= N; i++)
        fin >> t[i];
 
    double best = 0;
    for (int i = L; i <= U; i++)
    {
        int C = 0, T = 0;
        for (int j = 1; j <= N; j++)
        {
            C += c[j];
            T += t[j];
            if (j >= i)
            {
                if (best < (double) C / T)
                    best = (double) C / T;
                C -= c[j-i+1];
                T -= t[j-i+1];
            }
        }
    }
 
    fout << fixed << setprecision(3) << best << "\n";
 
}