#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<cmath>

 #include<vector>

 using namespace std;

 const int MAXN=+;

 const int INF=0x7fffffff;

 struct node

 {

     int data,weight,frequency;

     bool operator < (const node& x) const

     {

         return data<x.data;

     }

 }a[MAXN];

 int n,K,hash[MAXN];

 int f[MAXN][MAXN][MAXN];//f[i][j][w]由i~j组成的子树且每个点的权值都大于等于w的最小总代价 

 void init()

 {

     scanf("%d%d",&n,&K);

     for (int i=;i<=n;i++) scanf("%d",&a[i].data);

     for (int i=;i<=n;i++) scanf("%d",&a[i].weight),hash[i]=a[i].weight;

     for (int i=;i<=n;i++) scanf("%d",&a[i].frequency);

     sort(hash+,hash+n+);

     sort(a+,a+n+);

     int d=unique(hash+,hash+n+)-(hash+);

     for (int i=;i<=n;i++)

     {

         a[i].weight=lower_bound(hash+,hash+d+,a[i].weight)-hash;

     }

     for (int i=;i<=n;i++)

         a[i].frequency+=a[i-].frequency;//求出前缀和

 }

 void dp()

 {

     memset(f,0x3f,sizeof(f));

     for (int i=;i<=n+;i++)

         for (int w=;w<=n;w++) f[i][i-][w]=;

     //这个初始化注意一下(!)，下方(i=k/j=k)时用到

     for (int w=n;w;w--)//根据转移条件，显然w比较大的要先球出来，所以由大到小，放在最外层的循环

         for (int i=n;i;i--)

             for (int j=i;j<=n;j++)

                 for (int k=i;k<=j;k++)

                 {

                     if (a[k].weight>=w) f[i][j][w]=min(f[i][j][w],f[i][k-][a[k].weight]+f[k+][j][a[k].weight]+(a[j].frequency-a[i-].frequency));

                     //因为新增根节点后，每个节点的深度都+1,所以要加上访问的频率和

                     //因为可以取实数，所以后面a[k].weight不需要+1，下面的w也是同理

                     f[i][j][w]=min(f[i][j][w],f[i][k-][w]+f[k+][j][w]+(a[j].frequency+K-a[i-].frequency));

                 }

     int ans=INF;

     for (int i=;i<=n;i++)

         ans=min(ans,f[][n][i]);

     printf("%d",ans);

 }

 int main()

 {

     init();

     dp();

     return ;

 }