N, W = map(int, input().split())
weights, values = [list(map(int, input().split())) for _ in range(2)]
weight_to_value_sum = dict().fromkeys(weights, 0)
for w, v in zip(weights, values):
    weight_to_value_sum[w] += v
max_weight = max(weights)
ans = 0
for g in range(W, max_weight + 1):
    ans = max(
        ans, sum(weight_to_value_sum.get(t, 0) for t in range(g, max_weight + 1, g))
    )
print(ans)