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

using namespace std;

int main()
{
  const int b = 2e5;
  int n, w;
  cin >> n >> w;
  vector<int> x(n), 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> sum(b + 1);
  for (int i = 0; i < n; ++i) sum[x[i]] += y[i];
  vector<long long> all(b + 1);
  for (int i = 1; i <= b; ++i)
  {
    long long tmp = 0;
    for (int j = 1; i * j <= b; ++j) tmp += sum[i * j];
    all[i] = tmp;
  }
  long long ans = 0;
  for (int i = w; i <= b; ++i) ans = max(ans, all[i]);
  cout << ans << endl;
}