#include <iostream>
#include <vector>
#include <cmath>
#include <map>

std::vector<int> divisors (const int x, const int W) {
	std::vector<int> res;
	for (int d = 1; d <= std::sqrt(x); ++d) {
		if (x % d == 0) {
			if (x / d >= W) {
				res.push_back(x / d);
				if (d >= W && d * d != x) res.push_back(d);
			}
			else break;
		}
	}
	return res;
}

int main() {
	int N, W;
	std::cin >> N >> W;
	std::map<int, long long> s;
	std::vector<int> X(N), Y(N);
	for (int& x : X) std::cin >> x;
	for (int& y : Y) std::cin >> y;
	for (int i = 0; i < N; ++i) {
		for (int d : divisors(X[i], W)) {
			s[d] += Y[i];
		}
	}
	long long ans = 0;
	for (auto& p : s) {
		long long ysum = p.second;
		if (ans < ysum) ans = ysum;
	}
	std::cout << ans << std::endl;
}