#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
// using namespace atcoder;
// using mint = modint1000000007;
// const int mod = 1000000007;
// using mint = modint998244353;
// const int mod = 998244353;
// const int INF = 1e9;
const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i, l, r) for (int i = (l); i < (r); ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep2(i, l, r) for (int i = (r)-1; i >= (l); --i)
#define all(x) (x).begin(), (x).end()
#define allR(x) (x).rbegin(), (x).rend()
#define P pair<int, int>
template<typename A, typename B> inline bool chmax(A &a, const B &b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A &a, const B &b) { if (a > b) { a = b; return true; } return false; }
template <class T, class F>
T binarySearch(T ok, T ng, const F &f) {
	while (abs(ok - ng) > 1) {
		T mid = (ok + ng) / 2;
		(f(mid) ? ok : ng) = mid;
	}
	return ok;
}
//約数列挙
std::vector<long long> divisorEnumeration(long long n) {
	std::vector<long long> x;
	for (long long i = 1; i*i <= n; i++) {
		if (0 == n % i) {
			x.push_back(i);
			if (n != i * i) x.push_back(n / i);
		}
	}
	std::sort(x.begin(), x.end());
	return x;
}
int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int n; cin >> n;
	long long k; cin >> k;
	vector<long long>a(n), b(n);
	rep(i, n)cin >> a[i];
	rep(i, n)cin >> b[i];
	vector<vector<long long>>d(n);
	rep(i, n)d[i] = divisorEnumeration(a[i]);

	vector<vector<long long>>dp(n);
	rep(i, n) {
		dp[i].resize(d[i].size());
		rep(j, d[i].size()) {
			long long x = ((b[i] + d[i][j] - 1) / d[i][j])*d[i][j];
			dp[i][j] = x - b[i];
		}
	}
	vector<vector<long long>>dpMN(n);
	rep(i, n) {
		dpMN[i].resize(d[i].size() + 1);
		dpMN[i].back() = LINF;
		rrep(j, dpMN[i].size() - 1) {
			dpMN[i][j] = min(dpMN[i][j + 1], dp[i][j]);
			//chmin(dpMN[i][j], dpMN[i][j + 1]);
		}
	}



	long long mna = a[0];
	rep(i, n)chmin(mna, a[i]);
	auto f = [&](const long long target)->bool {
		long long sum = 0;
		rep(i, n) {
			int count = d[i].end() - lower_bound(all(d[i]), target);
			long long add = dpMN[i][d[i].size() - count];
			//	cout << i << " " << add << endl;
			sum += add;
			if (sum > k)return false;
		}
		return true;
	};
	//f(10);
	//return 0;
	auto ans = binarySearch<long long>(1, mna + 1, f);
	cout << ans << endl;
	return 0;
}