#include <cstdio>
#include <algorithm>
#include <deque>

using namespace std;

const double eps=0.0000001;
int cost[30010],timp[30010];
deque<int> v;
int n,l,u;
double st=0,dr=10000000,mid,sum[30010];

int ILLUMINATI_NOSCOPE_EXIST()
{
    v.clear();
    for(int i=1;i<=n;i++)
        sum[i]=sum[i-1]+cost[i]-timp[i]*mid;
    double maxx=-1;
    for(int i=l;i<=n;i++)
    {
        while(!v.empty())
            if(sum[v.back()]>=sum[i-l]) v.pop_back();
            else break;
        v.push_back(i-l);
        if(v.front()==i-u-1) v.pop_front();
        maxx=max(maxx,sum[i]-sum[v.front()]);
    }
    if(maxx>=0) return 1;
    else return 0;
}

int main()
{
    freopen("secv3.in","r",stdin);
    freopen("secv3.out","w",stdout);
    scanf("%d%d%d",&n,&l,&u);
    for(int i=1;i<=n;i++)
        scanf("%d",&cost[i]);
    for(int i=1;i<=n;i++)
        scanf("%d",&timp[i]);
    for(int i=1;i<=50;i++)
    {
        mid=(st+dr)/2;
        if(ILLUMINATI_NOSCOPE_EXIST()==1) st=mid;
        else dr=mid;
    }
    printf("%f",dr);
    return 0;
}