## https://yukicoder.me/problems/no/3502




def main():
    N, W = map(int, input().split())
    X = list(map(int, input().split()))
    Y = list(map(int, input().split()))

    max_w = max(W, max(X))
    x_map = [0 for _ in range(max_w + 1)]
    for i in range(N):
        x = X[i]
        y = Y[i]
        x_map[x] += y

    answer = [0] * (max_w + 1)
    for x in reversed(range(1, max_w + 1)):
        y = x
        while y <= max_w:
            answer[x] += x_map[y]
            y += x

    ans = 0
    for w in range(W, max_w + 1):
        ans = max(ans, answer[w])
    print(ans)









if __name__ == "__main__":
    main()