using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Runtime.Intrinsics.Arm;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, w) = (c[0], c[1]);
        var x = NList;
        var y = NList;
        var sum = new long[200_001];
        for (var i = 0; i < n; ++i) sum[x[i]] += y[i];
        var ans = 0L;
        for (var i = w; i < sum.Length; ++i)
        {
            var sub = 0L;
            for (var j = i; j < sum.Length; j += i) sub += sum[j];
            ans = Math.Max(ans, sub);
        }
        WriteLine(ans);
    }
}