#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
#include <chrono>
#include <fstream> 
using namespace std;

#define int long long
#define mp make_pair
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back

const int MOD = 998244353;//
const int FACTMAX = 2000005;//
const int CATALANMAX = 1000005;//

int fact[FACTMAX], invfact[FACTMAX], cat[CATALANMAX];

int expo(int a, int b){
	int res=1;
	a%=MOD;
	while (b){
		if (b&1)res=(res*a)%MOD;
		a=(a*a)%MOD;
		b>>=1;
	}
	return res;
}

int inv(int num){
	return expo(num, MOD-2);
}

void initfact(){
	fact[0]=1;
	for (int i=1; i<FACTMAX; ++i)fact[i]=(fact[i-1]*i)%MOD;
	invfact[FACTMAX-1]=inv(fact[FACTMAX-1]);
	for (int i=FACTMAX-2; i>=0; --i)invfact[i]=(invfact[i+1]*(i+1))%MOD;
}
 
int ncr(int n, int r){
	if (n<r||r<0)return 0;
	return (((fact[n]*invfact[r])%MOD)*invfact[n-r])%MOD;
}

int gcd(int a, int b){
	while (b){
		int t=a%b;
		a=b;
		b=t;
	}
	return a;
}

int lcm(int a, int b){
	int temp=gcd(a, b);
	a/=temp;
	b/=temp;
	return a*b*temp;
}

void initcatalan(int k){
	cat[0]=1;
	for (int i=1; i<CATALANMAX; ++i)cat[i]=(((fact[2*i]*invfact[i])%MOD)*invfact[i+1])%MOD;
}

int query(int a, int b) {
	cout<<"? "<<a<<" "<<b<<endl;
	int x;
	cin>>x;
	if (x==-1)exit(0);
	return x;
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	initfact();
	int t=1;
	//cin>>t;
	while (t--){
		int n, w, ans=0;
		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<int> vect(200005, 0);
		for (int i=0; i<n; ++i)vect[x[i]]+=y[i];
		for (int i=w; i<=200000; ++i){
			int res=0;
			for (int j=i; j<=200000; j+=i)res+=vect[j];
			ans=max(ans, res);
		}
		cout<<ans;
	}
}