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

using ll = long long;

constexpr ll INF = 1e12;
constexpr int LIMIT = 1e5 + 10;

vector<int> divisors(int n) {
    vector<int> lower, upper;

    for (int i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            lower.push_back(i);
            if (i != n / i) {
                upper.push_back(n / i);
            }
        }
    }

    reverse(upper.begin(), upper.end());
    
    vector<int> divisor;
    for (int l: lower) {
        divisor.push_back(l);
    }
    for (int u: upper) {
        divisor.push_back(u);
    }

    return divisor;
}


void solve() {
    int N;
    ll K;
    cin >> N >> K;

    vector<int> A(N);
    for (int i = 0; i < N; i++) {
        cin >> A[i];
    }

    vector<int> B(N);
    for (int i = 0; i < N; i++) {
        cin >> B[i];
    }

    vector need_op(N, vector<pair<int, ll>>());

    for (int i = 0; i < N; i++) {
        vector<pair<int, int>> op;
        for (int div: divisors(A[i])) {
            op.emplace_back(div, ((div - B[i]) % div + div) % div);
        }

        ll min_cnt = INF;
        reverse(op.begin(), op.end());
        for (auto [key, val]: op) {
            min_cnt = min(min_cnt, (ll)val);
            need_op[i].emplace_back(key, min_cnt);
        }

        reverse(need_op[i].begin(), need_op[i].end());
    }

    vector<ll> imos(LIMIT, 0LL);

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < need_op[i].size() - 1; j++) {
            int curr = need_op[i][j].first, to = need_op[i][j + 1].first;
            ll val = need_op[i][j + 1].second;

            imos[curr] += val;
            imos[to] -= val;
        }
        imos[need_op[i][need_op[i].size() - 1].first] += INF;
    }

    for (int i = 0; i < LIMIT - 1; i++) {
        imos[i + 1] += imos[i];
        if (imos[i + 1] > K) {
            cout << i + 1 << "\n";
            return;
        }
    }

}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    solve();

    return 0;
}