package no3502_GCD_knapsack;
import java.util.*;
public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int w = sc.nextInt();
		int max = 200001;
		long[] ans = new long[max];
		ArrayList<ArrayList<Integer>> l = new ArrayList<>();
		l.add(new ArrayList<>());
		for(int i = 1;i < max;i++) {
			l.add(new ArrayList<>());
		}for(int i = 1;i < max;i++) {
			for(int j = i;j < max;j += i) {
				l.get(j).add(i);
			}
		}
		int[] x = new int[n];
		int[] y = new int[n];
		for(int i = 0;i < n;i++) {
			x[i] = sc.nextInt();
		}for(int i = 0;i < n;i++) {
			y[i] = sc.nextInt();
		}for(int i = 0;i < n;i++) {
			for(int s:l.get(x[i])) {
				ans[s] += y[i];
			}
		}long out = 0;
		for(int i = w;i < max;i++) {
			out = Math.max(ans[i], out);
		}System.out.println(out);
	}

}