from math import gcd
def divisors(x):
  ret = []
  i = 1
  while (i**2 <= x):
    if x%i == 0:
      ret.append(i)
      if i != x//i:
        ret.append(x//i)
    i += 1
  return ret

n,w = map(int,input().split())
x = list(map(int,input().split()))
y = list(map(int,input().split()))

d = []
for xi in x:
	d += divisors(xi)
ss = sorted(set(d))
d0 = {v:i for i,v in enumerate(ss)}
d1 = {i:v for i,v in enumerate(ss)}

dp = [0 for _ in range(len(ss))]
for xi,yi in zip(x,y):
	ndp = [0 for _ in range(len(ss))]
	for i in range(len(ss)):
		ndp[i] = max(dp[i],ndp[i])
		ni = d0[gcd(xi,d1[i])]
		ndp[ni] = max(dp[i]+yi,ndp[ni])
	dp = ndp
ans = 0
for i in range(len(ss)):
	if d1[i] >= w:
		ans = max(dp[i],ans)
print(ans)