#include <cstdio>
#define fin  "secv3.in"
#define fout "secv3.out"
#define Nmax 30001
#define EPS  0.000000001

#define DBG
#define FL

int N,L,U,a[Nmax],b[Nmax];
//dq
double dq[Nmax],sum[Nmax];
int pz[Nmax],vf,pr;
//end_dq

double go(double X)
{	
	int i;
	double bst;

	for (i=1;i<=N;++i)
		sum[i]=sum[i-1] + (double)a[i] - (double)b[i]*X;

	vf=0; pr=1; 
	pz[1]=1; dq[1]=0;
	bst=sum[L];

	for (i=L+1;i<=N;++i)
	{
		if (pz[pr] < i-U) ++pr;
		while (vf>0 && dq[vf]>sum[i-L])
			--vf;
		++vf;
		dq[vf]=sum[i-L];
		pz[vf]=i-L;
		if (sum[i]-dq[pr] > bst)
			bst=sum[i]-dq[pr];
	#ifdef DBGG
		int j;
		printf("%lf\n",bst);
		for (j=pr;j<=vf;++j)
			printf("%lf ",dq[j]);
		printf("\n\n");
	#endif 
	}
	return bst;
}

int main() 
{
	int i;
	double hi,lo,m,tmp;

	freopen(fin,"r",stdin);
#ifdef FL
	freopen(fout,"w",stdout);
#endif 
	
	scanf("%d%d%d",&N,&L,&U);
	for (i=1;i<=N;++i)
		scanf("%d",&a[i]);
	for (i=1;i<=N;++i)
		scanf("%d",&b[i]);

	lo=0; hi=(double)Nmax;

	while (lo<hi)
	{
		m=(lo+hi)/2;
		tmp=go(m);
		
	#ifdef DBGg
		printf("%lf %lf %lf %lf\n",m,lo,hi,tmp);
	#endif
		if (tmp > 0 && tmp < EPS)
			break;
		if (tmp>EPS) 
			lo=m+EPS;
		if (tmp<0)
			hi=m-EPS;
	}
	int aux;
	m*=100;
	aux=(int)m;
	printf("%d.%d%d\n",aux/100,aux%100/10,aux%10);
	return 0;
}