import sys
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#####################################################################

"""

12

n = 2 は

gcd(X) >= W


"""

m = 2 * 10 ** 5 + 100
n, w = na()

x = na()
y = na()

f = [0] * m
for i in range(n):
    f[x[i]] += y[i]

for i in range(1, m):
    for j in range(i * 2, m, i):
        f[i] += f[j]

# print(f)
ans = 0
for i in range(w, m):
    ans = max(ans, f[i])

print(ans)