N, W = map(int, input().split())

X = list(map(int, input().split()))
Y = list(map(int, input().split()))

l = [0] * (2 * 10**5 + 1)

for x, y in zip(X, Y):
    i = 1
    # print(x)
    while i * i <= x:
        if x % i == 0:
            l[i] += y
            l[x // i] += y
        i += 1
max_l = -1
for i in range(W + 1, len(l)):
    if max_l < l[i]:
        max_l = l[i]
print(max_l)
# print(l)