#include <bits/stdc++.h>
#include <atcoder/all>

using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define all(x) begin(x), end(x)
template <class T> bool chmin(T& x, T y) {
	return x > y ? (x = y, true) : false;
}
template <class T> bool chmax(T& x, T y) {
	return x < y ? (x = y, true) : false;
}

using mint = atcoder::modint998244353;

void solve() {
	int n, w;
	cin >> n >> w;
	vector<int> x(n), y(n);
	rep(i, 0, n) cin >> x[i];
	rep(i, 0, n) cin >> y[i];
	int m = 2e5 + 10;
	vector<ll> gd(m);
	rep(i, 0, n) gd[x[i]] += y[i];
	for (int i = 1; i < m; i++) {
		for (int j = i * 2; j < m; j += i) gd[i] += gd[j];
	}
	ll ans = 0;
	rep(i, w, m) chmax(ans, gd[i]);
	cout << ans << '\n';
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout << fixed << setprecision(15);
	int t = 1;
	// cin >> t;
	while (t--) solve();
}