#include<stdio.h>
long long int h[40000007], l;
long long int comp_h(long long int a, long long int b)
{
	if (h[a] > h[b])
		return 1;
	else
		return -1;
}
void swap_h(long long int a, long long int b)
{
	long long int f = h[a];
	h[a] = h[b];
	h[b] = f;
	return;
}
void push(long long int ne)
{
	h[l] = ne;
	long long int p = l++;
	for (; p > 0; p = (p - 1) / 2)
		if (comp_h((p - 1) / 2, p) > 0)
			swap_h((p - 1) / 2, p);
	return;
}
long long int pop()
{
	swap_h(0, --l);
	long long int p = 0;
	for (;;)
	{
		if (2 * p + 2 < l)
		{
			if (comp_h(2 * p + 1, 2 * p + 2) > 0)
			{
				if (comp_h(p, 2 * p + 2) > 0)
					swap_h(p, 2 * p + 2);
				p = 2 * p + 2;
			}
			else
			{
				if (comp_h(p, 2 * p + 1) > 0)
					swap_h(p, 2 * p + 1);
				p = 2 * p + 1;
			}
		}
		else if (2 * p + 1 < l)
		{
			if (comp_h(p, 2 * p + 1) > 0)
				swap_h(p, 2 * p + 1);
			p = 2 * p + 1;
		}
		else
			break;
	}
	return h[l];
}
long long int div[40000007], sum[40000007], dd;
long long int find(long long int d)
{
	long long int min, mid, max;
	min = -1;
	max = dd;
	while (max - min > 1)
	{
		mid = (max + min) / 2;
		if (div[mid] < d)
			min = mid;
		else
			max = mid;
	}
	return max;
}
long long int x[200005], y[200005];
int main()
{
	long long int n, w;
	scanf("%lld %lld", &n, &w);
	long long int i, j;
	for (i = 0; i < n; i++)
		scanf("%lld", &x[i]);
	for (i = 0; i < n; i++)
		scanf("%lld", &y[i]);
	l = 0;
	for (i = 0; i < n; i++)
	{
		for (j = 1; j * j <= x[i]; j++)
		{
			if (x[i] % j > 0)
				continue;
			push(j);
			push(x[i] / j);
		}
	}
	div[0] = pop();
	dd = 1;
	while (l > 0)
	{
		div[dd] = pop();
		if (div[dd] != div[dd - 1])
			dd++;
	}
	for (i = 0; i < n; i++)
	{
		for (j = 1; j * j < x[i]; j++)
		{
			if (x[i] % j > 0)
				continue;
			sum[find(j)] += y[i];
			sum[find(x[i] / j)] += y[i];
		}
		if (j * j == x[i])
			sum[find(j)] += y[i];
	}
	long long int ans = 0;
	for (i = 0; i < dd; i++)
	{
		if (div[i] < w)
			continue;
		if (ans < sum[i])
			ans = sum[i];
	}
	printf("%lld\n", ans);
	return 0;
}