#include <bits/stdc++.h>
using namespace std;

using ll = long long;
[[maybe_unused]] constexpr ll INF = (1LL << 60) - 1;

void solve() {
    ll n, k;
    cin >> n >> k;
    vector<ll> a(n);
    for (ll i = 0; i < n; ++i) {
        cin >> a[i];
    }
    vector<ll> b(n);
    for (ll i = 0; i < n; ++i) {
        cin >> b[i];
    }
    ll ma = *max_element(a.begin(), a.end());
    vector<vector<ll>> div(ma + 1);
    for (ll i = 1; i <= ma; ++i) {
        for (ll j = i; j <= ma; j += i) {
            div[j].push_back(i);
        }
    }

    // 二分探索: p 未満で条件を満たさず p 以上で条件を満たすような p を返す
    auto check = [&](ll p) -> bool {
        ll cnt = 0;
        for (ll i = 0; i < n; ++i) {
            ll mn = INF;
            vector<ll>& d = div[a[i]];
            ll l = lower_bound(d.begin(), d.end(), p) - d.begin();
            ll r = d.size();
            for (ll j = l; j < r; ++j) {
                ll c = ((-b[i]) % d[j] + d[j]) % d[j];
                mn = min(mn, c);
            }
            if (mn == INF) return false;
            cnt += mn;
        }
        return cnt <= k;
    };

    auto binSearch = [&]() -> ll {
        ll ng = 1;
        ll ok = ma + 1;
        while (ok - ng > 1) {
            ll mid = (ng + ok) / 2;
            if (!check(mid)) ok = mid;
            else ng = mid;
        }
        return ng;
    };

    cout << binSearch() << "\n";
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}