import sys, math
sys.setrecursionlimit(10**8)
sys.set_int_max_str_digits(0)
INF = 1e18
MOD = 998244353
from bisect import bisect_left, bisect_right
from collections import deque, defaultdict, Counter
from itertools import product, combinations, permutations, groupby, accumulate
from heapq import heapify, heappop, heappush
input = sys.stdin.readline
def I():   return input().rstrip()
def II():  return int(input().rstrip())
def IS():  return input().rstrip().split()
def MII(): return map(int, input().rstrip().split())
def LI():  return list(input().rstrip())
def TII(): return tuple(map(int, input().rstrip().split()))
def LII(): return list(map(int, input().rstrip().split()))
def LSI(): return list(map(str, input().rstrip().split()))
def GMI(): return list(map(lambda x: int(x) - 1, input().rstrip().split()))
def kiriage(a, b): return (a+b-1)//b

def main():
    N, K = MII()
    A = LII()

    def make_divisors(n):
        lower_divisors , upper_divisors = [], []
        i = 1
        while i*i <= n:
            if n % i == 0:
                lower_divisors.append(i)
                if i != n // i:
                    upper_divisors.append(n//i)
            i += 1
        return lower_divisors + upper_divisors[::-1]

    A_divs = []
    for a in A:
        A_divs.append(make_divisors(a)[::-1])
    B = LII()

    def solve(m): # 全ペアの GCD を m以上にできますか？
        if m == 1:
            return True

        total_cnt = 0
        for i in range(N):
            b = B[i]
            cnt = K + 1

            # a の約数を大きいものから見る
            for div in A_divs[i]:
                if div == 1:
                    break
                if div < m:
                    break
                # B[i] を div の約数になるまでいくらコストが必要か？
                cost = b%div
                if cost != 0:
                    cost = div - cost
                # 最小か？            
                if cost < cnt:
                    cnt = cost

            total_cnt += cnt

        return total_cnt <= K

    ok = 1
    ng = max(A) + 1


    for i in range(10):
        if solve(ng - i):
            exit(print(ng - i))

    while abs(ok - ng) != 1:
        mid = (ok + ng)//2
        if solve(mid):
            ok = mid
        else:
            ng = mid

    print(ok)

if __name__ == "__main__":
    main()