import sys


def main() -> None:
    data = list(map(int, sys.stdin.buffer.read().split()))
    if not data:
        return

    n, w = data[0], data[1]
    xs = data[2:2 + n]
    ys = data[2 + n:2 + 2 * n]

    max_x = max(xs)
    value_by_weight = [0] * (max_x + 1)
    for x, y in zip(xs, ys):
        value_by_weight[x] += y

    ans = 0
    for g in range(w, max_x + 1):
        total = 0
        for multiple in range(g, max_x + 1, g):
            total += value_by_weight[multiple]
        if total > ans:
            ans = total

    print(ans)


if __name__ == "__main__":
    main()