import math
from bisect import bisect_left

LIMIT = 10**5 + 1
INF = 10**9


def factorize(n):
    factorized = []
    for i in range(1, math.isqrt(n) + 1):
        if n % i == 0:
            factorized.append(i)
            factorized.append(n // i)

    if math.isqrt(n) ** 2 == n:
        factorized.pop()

    return factorized


N, K = [int(s) for s in input().split()]
A = [int(s) for s in input().split()]
B = [int(s) for s in input().split()]

need_op = [dict() for _ in range(N)]

for i, (a, b) in enumerate(zip(A, B)):
    for fac in factorize(a):
        need_op[i][fac] = (fac - b) % fac

    min_cnt = INF

    for key in sorted(need_op[i], reverse=True):
        min_cnt = min(need_op[i][key], min_cnt)
        need_op[i][key] = min_cnt

keys = [list(sorted(need_op[i])) for i in range(N)]


def is_ok(mid):
    cnt = 0

    for i, key in enumerate(keys):
        idx = bisect_left(key, mid)
        cnt += need_op[i][key[idx]]

    return cnt <= K


ok, ng = 0, min(A) + 1
while abs(ok - ng) > 1:
    mid = (ok + ng) // 2

    if is_ok(mid):
        ok = mid
    else:
        ng = mid

print(ok)