#include <cstdio>

#define file_in "secv3.in"
#define file_out "secv3.out"

#define Nmax 30110

int n,l,u;
double suma1,suma2;
double c[Nmax],t[Nmax];

int main()
{
	int i,j,nr;
	freopen(file_in,"r",stdin);
	
	scanf("%d %d %d", &n,&l,&u);

	for (i=1;i<=n;++i)
		 scanf("%lf", &c[i]);
	for (i=1;i<=n;++i)
		 scanf("%lf", &t[i]);


	fclose(stdin);
	
	double max=0.0;

	for (i=1;i<=n;++i)
	{
		suma1=c[i];
		suma2=t[i];
		nr=1;
		if (nr>=l && nr<=u && suma1/suma2>max)
			max=suma1/suma2;
		
		for (j=i+1;j<=n;++j)
		{
			suma1+=c[j];
			suma2+=t[j];
			nr++;
			if (nr>=l && nr<=u && suma1/suma2>max)
					max=suma1/suma2;
			if (nr>u) break;

		}
	}

	freopen(file_out,"w",stdout);
    printf("%.2lf", max);

	fclose(stdout);

	return 0;
}