#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
typedef long long ll;
typedef pair<ll, ll> P;
// typedef tuple<ll, ll, ll> T;
template<typename T>bool chmax(T& a, const T& b) { if (a < b) { a = b;return true; } else { return false; } }
template<typename T>bool chmin(T& a, const T& b) { if (a > b) { a = b;return true; } else { return false; } }
template<class... Args> void dbg(Args&&... args) { ((cout << args << ' '), ...);cout << '\n'; }

const int di[] = { -1,0,1,0 };
const int dj[] = { 0,-1,0,1 };
const long long INF = 6000000000000000000;
const int inf = 1001001001;


int main(void) {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n; cin >> n;
    ll k; cin >> k;
    vector<int> a(n, 0), b(n, 0);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    for (int i = 0; i < n; i++) {
        cin >> b[i];
    }
    vector<set<ll>> c(n);

    using T = tuple<ll, ll>;
    priority_queue<T, vector<T>, greater<T>> pq;
    for (int j = 0; j < n; j++) {
        ll g = gcd(a[j], b[j]);
        for (long long i = g; i * i <= a[j]; ++i) {
            if (a[j] % i == 0) {
                c[j].insert(i);
                // 重複しないならば i の相方である N/i も push
                if (a[j] / i != i)c[j].insert(a[j] / i);
            }
        }
        pq.emplace(g, j);
    }

    int ans = inf;
    while (pq.size()) {
        auto [g, p] = pq.top();pq.pop();
        // dbg(g, p, k);
        auto it = c[p].find(g);
        it++;
        int x = *it;
        int cnt = b[p] % x;
        if (k - (x - cnt) >= 0)k -= x - cnt;
        else break;

        b[p] += x - cnt;
        ll h = gcd(a[p], b[p]);
        // dbg(h, p);
        if (h == a[p])continue;
        pq.emplace(h, p);
    }
    for (int i = 0; i < n; i++) {
        chmin(ans, gcd(a[i], b[i]));
    }
    cout << ans << "\n";
}