#include <fstream>

using namespace std;
ifstream fin ("secv3.in");
ofstream fout ("secv3.out");
int c[30005], t[30005], d[30005];
int main()
{
    int n, mn, mx;
    fin >> n >> mn >> mx;
    for(int i = 1; i <= n; ++i) fin >> c[i];
    for(int i = 1; i <= n; ++i) fin >> t[i];
    double ans = 0;
    int F = 1, L = 0, sum1 = 0, sum2 = 0;
    for(int i = 1; i <= mn; ++i) d[++L] = i, sum1 += c[i], sum2 += t[i];
    ans = max(ans, (double) sum1 / sum2);
    for(int i = mn + 1; i <= n; ++i) {
            sum1 += c[i], sum2 += t[i];
            ans = max(ans, (double) sum1 / sum2);
            d[++L] = i;
        while(L - F + 1 > mn && (double) (sum1 - c[d[F]]) / (sum2 - t[d[F]])) {
            sum1 -= c[d[F]], sum2 -= t[d[F]], ++F;
            ans = max(ans, (double) sum1 / sum2);
        }
        if(L - F + 1 == mx) sum1 -= c[d[F]], sum2 -= t[d[F]], ++F;
        ans = max(ans, (double) sum1 / sum2);
    }
    while(L - F + 1 > mn && (double) (sum1 - c[d[F]]) / (sum2 - t[d[F]])) {
            sum1 -= c[d[F]], sum2 -= t[d[F]], ++F;
            ans = max(ans, (double) sum1 / sum2);
        }
    fout << ans;
    return 0;
}