//https://infoarena.ro/problema/secv3
//#pragma GCC optimize ("Ofast")
//#pragma GCC optimize ("fast-math")
//#pragma GCC optimize ("unroll-loops")
//#define _USE_MATH_DEFINES
#include <iostream>
#include <fstream>
#include <vector>
//#include <cstring>
//#include <cmath>
//#include <bitset>
//#include <queue>
//#include <utility>
//#include <algorithm>
//#include <string>
//#include <map>
//#include <climits>
#include <iomanip>
using namespace std;

ifstream fin("secv3.in");
ofstream fout("secv3.out");

int c[30005], t[30005];
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int n, l, u, i, j;
	float maxi = 0;
	int sumc = 0, sumt = 0;
	
	fin >> n >> l >> u;
	for (i = 1; i <= n; ++i)
	{
		fin >> c[i];
	}
	for (i = 1; i <= n; ++i)
	{
		fin >> t[i];
	}

	for (i = 1; i <= n - l + 1; ++i)
	{
		sumc = 0;
		sumt = 0;

		//cout << i << " ";
		for (j = i + l - 1; j <= i + u - 1 && j <= n; ++j)
		{
			//cout << j << " ";
			sumc += c[i];
			sumt += t[i];
			//cout << sumc << " " << sumt << "\n";
			maxi = max(maxi, ((float)sumc / sumt));
		}

		//cout << "\n";
	}

	fout << setprecision(2) << maxi;

	return 0;
}