#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

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

    int N, W;
    cin >> N >> W;

    const int MAX_X = 200000;
    vector<int> X(N);
    vector<long long> Y(N);
    for (int i = 0; i < N; ++i) cin >> X[i];
    for (int i = 0; i < N; ++i) cin >> Y[i];

    vector<long long> weight_val(MAX_X + 1, 0);
    for (int i = 0; i < N; ++i) {
        weight_val[X[i]] += Y[i];
    }

    long long ans = 0;

    for (int g = W; g <= MAX_X; ++g) {
        long long current_sum = 0;
        for (int multiple = g; multiple <= MAX_X; multiple += g) {
            current_sum += weight_val[multiple];
        }
        ans = max(ans, current_sum);
    }

    cout << ans << endl;

    return 0;
}