#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <algorithm>
#include <utility>
#include <string>
#include <functional>
#include <sstream>
#include <fstream>
using namespace std;
#define FOR(i,a,b) for (i=(a);i<=(b);i++)
#define fori(it,v) for (it=(v).begin();it!=(v).end();it++)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(c) c.begin(),c.end()
#define pf push_front
#define popb pop_back
#define popf pop_front
typedef pair<int,int> ii;
FILE *in,*out;
int U,L,n;
long long q[30050],s[30050],c[30050],a[30050],b[30050];
int ver(long long  x)
{
	long long maxv=-(1<<30),i,p,u;
	FOR(i,1,n)
	{
		c[i]=a[i]-x*b[i];
		s[i]=s[i-1]+c[i];
	}
	p=1;
	u=0;
	FOR(i,1,n-L+1)
	{
		while (p<=u&&i+L-1-q[p]+1>U)
			p++;
		while (p<=u&&s[i+L-1]-s[i-1]>s[i+L-1]-s[q[u]-1])
			u--;
		u++;
		q[u]=i;
		maxv=max(maxv,s[i+L-1]-s[q[p]-1]);
	}
	if (maxv>=0)
		return 0;
	return 1;
}
int main()
{
	long long i,rez;
	in=fopen("secv3.in","r");
	out=fopen("secv3.out","w");
	fscanf(in,"%d%d%d",&n,&L,&U);
	FOR(i,1,n)
	{
		fscanf(in,"%lld",&a[i]);
		a[i]*=100;
	}
	FOR(i,1,n)
		fscanf(in,"%lld",&b[i]);
	rez=0;
	for(i=(((long long)1)<<40);i;i>>=1)
	{
		rez+=i;
		if (ver(rez))
			rez-=i;
	}
	fprintf(out,"%lld.%lld%lld\n",rez/100,(rez%100)/10,rez%10);
	fclose(in);
	fclose(out);
        return 0;
}