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

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

    int N, W;
    cin >> N >> W;
    const int inf = 200000;
    vector<int> X(N);
    for (int i = 0; i < N; ++i) cin >> X[i];
    
    vector<long long> sum(inf + 1, 0);
    for (int i = 0; i < N; ++i) {
        int y;
        cin >> y;
        sum[X[i]] += y;
    }

    long long maxx = 0;

    for (int g = W; g <= inf; ++g) {
        long long cur = 0;
        for (int i = g; i <= inf; i += g) {
            cur += sum[i];
        }
        
        if (cur > 0) {
            maxx = max(maxx, cur);
        }
    }

    cout << maxx << endl;

    return 0;
}