n, k = list(map(int, input().split()))
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = [[] for _ in range(n)]
D = [[] for _ in range(n)]
P = [[] for _ in range(10**5+1)]
for i in range(2, 10**5+1):
    for j in range(i, 10**5+1, i):
        P[j].append(i)
for i in range(n):
    a, b = A[i], B[i]
    if a == 1:
        print(1)
        exit()
    S = [(-1, 0)]
    for p in P[a]:
        if not b % p:
            cost = 0
        else:
            cost = p - b % p
        while S and S[-1][0] >= cost:
            S.pop()
        S.append((cost, p))
    for cost, p in S[1:]:
        C[i].append(cost)
        D[i].append(p)
from bisect import bisect_left as bs
l = 1
r = 10 ** 5 + 2
while r - l > 1:
    m = (l + r) >> 1
    t = 0
    for i in range(n):
        if D[i][-1] < m:
            r = m
            break
        else:
            t += C[i][bs(D[i], m)]
    else:
        if t <= k:
            l = m
        else:
            r = m

print(l)