#include<stdio.h>
#include<time.h>


int main()
{
	freopen("secv3.in","rt",stdin);
	freopen("secv3.out","wt",stdout);
	long n,min,i,j,max,v[32*1024],t[32*1024];
	long s1,s2;
	double sol=0;
	scanf("%ld%ld%ld",&n,&min,&max);
	double start;
	start=(double)clock();

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

	for(i=min;i<=max;i++)
		{
		if((double) clock()-start >(double) CLOCKS_PER_SEC/3) break;
		s1=0;
		s2=0;
		for(j=1;j<=i;j++)
			{s1+=v[j];s2+=t[j];}
		if((double)s1/s2>sol) sol= (double)s1/s2;
		/*for(j=i+1;j<=n;j++)
			{
			s1+=v[j]-v[j-i];
			s2+=t[j]-t[j-i];
			if((double)s1/s2>sol) sol= (double)s1/s2;
			}*/
		}
	printf("%.4lf",sol);

	return 0;
}