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

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N,W; cin >> N >> W;
    int n = 200000;
    vector<long long> V(n+1);
    vector<int> X(N),Y(N);
    for(auto &x : X) cin >> x;
    for(auto &y : Y) cin >> y;
    for(int i=0; i<N; i++){
        int x = X.at(i),y = Y.at(i);
        V.at(x) += y;
    }
    long long answer = 0;
    for(int g=W; g<=200000; g++){
        long long now = 0;
        for(int i=g; i<=n; i+=g) now += V.at(i);
        answer = max(answer,now);
    }
    cout << answer << endl;
}