#include <fstream>
#include <cstdio>
#include <deque>
using namespace std;

#define NMax 30005
#define eps 0.001

int n,l,u;
int c[NMax],t[NMax];
double sum[NMax];

int solve(double x)
{
    int i;
    deque<int> dq;

    for(i=1;i<=n;++i) sum[i]=sum[i-1]+c[i]-x*t[i];

    dq.push_back(0);
    for(i=l;i<=n;++i)
    {
        while(!dq.empty() && sum[dq.back()]>=sum[i-l]) dq.pop_back();
        dq.push_back(i-l);

        while(dq.front()<=i-u) dq.pop_front();

        if(sum[i]-sum[dq.front()]>=0) return 1;
    }

    return 0;
}

int main()
{
    int i;

    ifstream f("secv3.in");
    f>>n>>l>>u;
    for(i=1;i<=n;++i) f>>c[i];
    for(i=1;i<=n;++i) f>>t[i];
    f.close();

    double mij,st=0,dr=1000;
    while(dr-st>eps)
    {
        mij =(st+dr)/2.0;
        if( solve(mij) ) st=mij;
        else dr=mij;
    }

    FILE *g=fopen("secv3.out","wt");
    fprintf(g,"%0.2lf\n",mij);
    fclose(g);

    return 0;
}