"""
ばかでごめんなさい
"""

from math import isqrt

mod = 998244353

II = lambda : int(input())
MI = lambda : (int(_) for _ in input().split())
LI = lambda : list(int(_) for _ in input().split())

n, mi = MI()
x = LI()
y = LI()

lim = 2 * 10 ** 5
s = [0] * (lim + 1)
for i in range(n):    
    s[x[i]] += y[i]

w = [0] * (lim + 1)
for p in range(1, lim+1):
    for q in range(p, lim+1, p):
        w[p] += s[q]

print(max(w[mi:]))