#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
ifstream f("secv3.in");
ofstream g("secv3.out");
const int N=30001;
long long d[N];
long long sum,n,l,u,st,dr=-1;
double c[N],t[N],rez=-10001,nr;
int main()
{
    f>>n>>l>>u;
    for(int i=1;i<=n;i++){
        f>>nr;
        c[i]=c[i-1]+nr;
    }
    for(int i=1;i<=n;i++){
        f>>nr;
        t[i]=t[i-1]+nr;
    }
    for(int i=1;i<=n;i++){
        if(i-l>0){
            if(st<=dr && d[st] == i-u-1)
               ++st;
            while(st<=dr && c[i-l]/t[i-l] >= c[d[dr]]/t[d[dr]])
               --dr;
            d[++dr]=i-l;
            rez = max(rez, (c[i] - c[d[st]])/(t[i]-t[d[st]]));
        }
    }
    rez=floor(rez*100)/100;
    g<<rez;
    return 0;
}