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

int main(){
  using ll=long long;
  int m=3e5;
  vector<vector<int>> g(m);
  for (int i=1;i<m;i++) for (int j=i;j<m;j+=i) g[i].push_back(j);
  int n,w;
  cin>>n>>w;
  vector<ll> x(n),y(n);
  vector<ll> sum(m);
  for (int i=0;i<n;i++) cin>>x[i];
  for (int i=0;i<n;i++) cin>>y[i],sum[x[i]]+=y[i];
  ll ans=0;
  for (int i=w;i<m;i++){
    ll s=0;
    for (int mul:g[i]) s+=sum[mul];
    ans=max(ans,s);
  }
  cout<<ans<<endl;
}