#include <cstdio>

using namespace std;

int v[30005], t[30005];
int n, l, r;

int ok(double med){
    int i, j = 0, s = 0;
    for(i = l;i <= n;i++){
        if(i - j > r){
            j++;
        }
        while(j < i && (double)(v[i] - v[j]) / (t[i] - t[j]) < med)
            j++;
        if(i - j >= l)
            return 1;
    }
    return 0;
}

double bs(double st, double dr){
    double med;
    int i;
    for(i = 0;i < 50;i++){
        med = (st + dr) / 2;
        if(ok(med))
            st = med;
        else
            dr = med;
    }
    return med;
}

int main()
{
    freopen("secv3.in", "r", stdin);
    freopen("secv3.out", "w", stdout);
    int i;
    scanf("%d%d%d", &n, &l, &r);
    for(i = 1;i <= n;i++){
        scanf("%d", &v[i]);
        v[i] += v[i - 1];
    }
    for(i = 1;i <= n;i++){
        scanf("%d", &t[i]);
        t[i] += t[i - 1];
    }
    printf("%.2lf", bs(0.0, 1000.0));
    return 0;
}