#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";

}