#include <bits/stdc++.h>

using namespace std;

ifstream fin("secv3.in");
ofstream fout("secv3.out");
int n, u, l, i, c[30002], t[30002];
float st = 1, r;

int main(){
    fin >> n >> l >> u;
    for(i = 1; i <= n; i++) {
        fin >> c[i];
        c[i] += c[i - 1];
    }
    for(i = 1; i <= n; i++) {
        fin >> c[i];
        t[i] += t[i - 1];
    }

    for(i = 1; i <= n; i++) {
        if(i - u > st) st++;

        if(i < l) continue;

        if(1.0 * (c[i] - c[st - 1]) / (t[i] - t[st - 1]) <= 1.0 * (c[i] - c[i - l]) / (t[i] - t[i - l])) st = i - l + 1;
        r = max(r, 1.0 * (c[i] - c[st - 1]) / (t[i] - t[st - 1]));
    }
    fout << r;

	return 0;
}