from collections import defaultdict
n, w = map(int,input().split())
x = list(map(int,input().split()))
y = list(map(int,input().split()))

def GCD(a, b):
    while b != 0:
        tmp = b
        b = a % b
        a = tmp
    return a

rng = max(x) - w
if rng < 0:
    print(0)
    exit(0)

d = defaultdict()
d[0] = 0
for i in range(n):
    if x[i] < w:
        continue
    tmp = d.copy()
    for k, v in tmp.items():
        gcd = GCD(k, x[i])
    if gcd >= w:
        tmp[gcd] = v + y[i]
    d[x[i]] = y[i]
    d.update(tmp)
      
print(max(d.values()))