import sys


def main():
    data = list(map(int, sys.stdin.buffer.read().split()))
    n, w = data[0], data[1]
    x = data[2:2 + n]
    y = data[2 + n:2 + 2 * n]

    mx = max(x)
    if w > mx:
        print(0)
        return

    val = [0] * (mx + 1)
    for a, b in zip(x, y):
        val[a] += b

    ans = 0
    for d in range(w, mx + 1):
        s = 0
        for k in range(d, mx + 1, d):
            s += val[k]
        if s > ans:
            ans = s

    print(ans)


if __name__ == "__main__":
    main()