N, W = map(int, input().split())
M = 2 * 10**5 + 1
L = [0] * M
X = list(map(int, input().split()))
Y = list(map(int, input().split()))
for i in range(N):
    L[X[i]] += Y[i]
ans = 0
for i in range(W, M):
    s = 0
    for j in range(i, M, i):
        s += L[j]
    ans = max(ans, s)
print(ans)