#include <bits/stdc++.h>

using namespace std;

using pii = pair<int, int>;
using ll = long long;
const int N = 2000010, MOD = 998244353, INF = 0x3f3f3f3f;
int n, m, w[N];


ll f[N], x[N];
int a[N], b[N];
void solve() {
    scanf("%d%d", &n, &m);
    for (int i = 1; i < n + 1; i++) scanf("%d", a + i);
    for (int i = 1; i < n + 1; i++) scanf("%d", b + i), x[a[i]] += b[i];
    ll res = 0;
    for (int i = m; i <= 200000; i++) {
        ll sum = 0;
        for (int j = i; j <= 200000; j += i) sum += x[j];
        res = max(sum, res);
    }
    printf("%lld\n", res);
}

int main() {
    int T = 1;
    // cin >> T;
    while (T--) solve();
    return 0;
}