from math import gcd
from collections import defaultdict

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 = defaultdict(int)
for xi,yi in zip(x,y):
	for p in divisors(xi):
		d[p] += yi
ans = 0
for ky,vl in d.items():
	if ky >= w:
		ans = max(vl,ans)
print(ans)