#include <iostream>
#include <iomanip>
#include <cassert>
#include <vector>
#include <algorithm>
#include <utility>
#include <numeric>
#include <tuple>
#include <ranges>
#include <random>
// #include "Src/Number/IntegerDivision.hpp"
// #include "Src/Utility/BinarySearch.hpp"
// #include "Src/Sequence/CompressedSequence.hpp"
// #include "Src/Sequence/RunLengthEncoding.hpp"
// #include "Src/Algebra/Group/AdditiveGroup.hpp"
// #include "Src/DataStructure/FenwickTree/FenwickTree.hpp"
// #include "Src/DataStructure/SegmentTree/SegmentTree.hpp"
// #include "Src/DataStructure/DisjointSetUnion/DisjointSetUnion.hpp"
// #include "Src/DataStructure/Heap/BinaryHeap.hpp"


#include <cstdint>
#include <cstddef>

namespace zawa {

using i16 = std::int16_t;
using i32 = std::int32_t;
using i64 = std::int64_t;
using i128 = __int128_t;

using u8 = std::uint8_t;
using u16 = std::uint16_t;
using u32 = std::uint32_t;
using u64 = std::uint64_t;

using usize = std::size_t;

} // namespace zawa


#include <type_traits>

namespace zawa {

template <class T>
class PrimeFactor {
    static_assert(std::is_unsigned_v<T>, "T must be unsigned integer");
private:
    T factor_{};
    u32 exponent_{};

public: 
    PrimeFactor() = default;

    PrimeFactor(T factor, u32 exponent) : factor_{factor}, exponent_{exponent} {}

    inline T factor() const noexcept {
        return factor_;
    }

    inline u32 exponent() const noexcept {
        return exponent_;
    }

    friend bool operator<(const PrimeFactor<T>& lhs, const PrimeFactor<T>& rhs) {
        return lhs.factor() != rhs.factor() ?
            lhs.factor() < rhs.factor() :
            lhs.exponent() < rhs.exponent();
    }

    friend bool operator>(const PrimeFactor<T>& lhs, const PrimeFactor<T>& rhs) {
        return lhs.factor() != rhs.factor() ?
            lhs.factor() > rhs.factor() :
            lhs.exponent() > rhs.exponent();
    }
};

} // namespace zawa

#include <concepts>

namespace zawa {

class LinearSieve {
public:

    using V = u32;
    using F = PrimeFactor<V>;

private:

    std::vector<V> primes_;
    std::vector<V> lpf_;

public:

    explicit LinearSieve(V n) : primes_{}, lpf_(n + 1) {
        for (V i{2} ; i <= n ; i++) {
            if (!lpf_[i]) {
                lpf_[i] = i;
                primes_.emplace_back(i);
            }
            for (V p : primes_) {
                if (static_cast<u64>(p) * i > n) break;
                lpf_[p * i] = p;
            }
        }
    }

    V size() const noexcept {
        return static_cast<V>(lpf_.size()) - 1;
    }

    bool isPrime(V x) const noexcept {
        assert(x < lpf_.size());
        return lpf_[x] == x;
    }

    bool operator[](V x) const noexcept {
        assert(x < lpf_.size());
        return lpf_[x] == x;
    }

    std::vector<V> primes() const {
        return primes_;
    }

    // @note: response array is not sorted.
    template <std::integral T = V>
    std::vector<T> divisor(V x) const {
        assert(0u < x and x < lpf_.size());
        std::vector<T> res(1, 1u);
        while (x > 1) {
            V factor{lpf_[x]};
            u32 exponent{};
            while (lpf_[x] == factor) {
                exponent++;
                x /= lpf_[x];
            }
            usize line{res.size()};
            V now{1};
            for (u32 i{} ; i < exponent ; i++) {
                now *= factor;
                for (usize j{} ; j < line ; j++) {
                    res.emplace_back(static_cast<T>(res[j] * now));
                }
            }
        }
        return res;
    }

    std::vector<F> factorize(V x) const {
        assert(0u < x and x < lpf_.size());
        std::vector<F> res;
        while (x > 1) {
            V factor{lpf_[x]};
            u32 exponent{};
            while (lpf_[x] == factor) {
                exponent++;
                x /= lpf_[x];
            }
            res.emplace_back(factor, exponent);
        }
        return res;
    }

    i32 mobius(V x) const {
        assert(0u < x and x < lpf_.size());
        i32 res = 1;
        while (x > 1u) {
            V factor = lpf_[x];
            u32 exp = 0;
            while (lpf_[x] == factor) {
                x /= factor;
                exp++;
            }
            if (exp >= 2u) return 0;
            res *= -1;
        }
        return res;
    }
};

} // namespace zawa
namespace zawa {}
using namespace zawa;
// #include "atcoder/modint"
// using mint = atcoder::modint998244353;
// #include <array>
// #include <bit>
// #include <bitset>
// #include <climits>
// #include <cmath>
// #include <set>
// #include <unordered_set>
// #include <map>
// #include <unordered_map>
// #include <optional>
// #include <queue>
// #include <stack>
// #include <deque>
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
using namespace std;
template <class T, class U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    os << '(' << p.first << ',' << p.second << ')';
    return os;
}
template <class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    for (int i = 0 ; i < ssize(v) ; i++)
        os << v[i] << (i + 1 == ssize(v) ? "" : " ");
    return os;
}
/*
 */
int main() {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);
    cout << fixed << setprecision(20);
#if !defined DEBUG
    int N,W;
    cin >> N >> W;
    vector<int> X(N),Y(N);
    for (auto& x : X)
        cin >> x;
    for (auto& x : Y)
        cin >> x;
    const int MAX = 200020;
    LinearSieve siv{MAX};
    vector<long long> ans(MAX+1);
    for (int i = 0 ; i < N ; i++)
        for (int d : siv.divisor<int>(X[i]))
            ans[d] += Y[i];
    long long val = 0;
    for (int i = W ; i <= MAX ; i++)
        val = max(val,ans[i]);
    cout << val << '\n';
#else
    mt19937_64 mt{random_device{}()};
    for (int testcase = 0 ; ; ) {
        cerr << "----------" << ++testcase << "----------" << endl;
        
        auto a = solve(), b = naive();
        if (a != b) {
            // print testcase

            cerr << "you: " << a << endl;
            cout << "correct: " << b << endl;
            exit(0);
        }
    }
#endif
}