#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<queue>

 #include<algorithm>

 #define N 3000

 #define inf 0x3f3f3f3f

 #define M 4000005

 using namespace std;

 int n,m;

 int tot;

 int head[N],nxt[M],ver[M],f[M];

 void add(int a,int b,int c)

 {

     tot++;nxt[tot]=head[a];head[a]=tot;ver[tot]=b;f[tot]=c;

     tot++;nxt[tot]=head[b];head[b]=tot;ver[tot]=a;f[tot]=;

 }

 int S,T;

 int ch[N];int cur[N];

 int zeng(int a,int b)

 {

     if(a==T)return b;

     int r=;

     for(int i=cur[a];i&&b>r;i=nxt[i])

     {

         if(ch[ver[i]]==ch[a]+&&f[i])

         {

             int t=zeng(ver[i],min(b-r,f[i]));

             r+=t;f[i]-=t;f[i^]+=t;

             if(f[i]>)cur[a]=i;

         }

     }

     if(!r)ch[a]=-;

     return r;

 }

 bool tell()

 {

     memset(ch,-,sizeof(ch));

     ch[S]=;

     queue<int>q;

     q.push(S);

     while(!q.empty())

     {

         int tmp=q.front();q.pop();

         for(int i=head[tmp];i;i=nxt[i])

         {

             if(f[i]&&ch[ver[i]]==-)

             {

                 ch[ver[i]]=ch[tmp]+;

                 q.push(ver[i]);

             }

         }

     }

     return ch[T]!=-;

 }

 int dinic()

 {

     int r=,t;

     while(tell())

     {

         for(int i=;i<=T;i++)cur[i]=head[i];

        while(t=zeng(S,inf))r+=t;

     }

     return r;

 }

 int v[N];

 int ans;

 int main()

 {

     tot=;

     scanf("%d%d",&n,&m);int t1,t2;

     S=;T=n+m+;

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

     {

         int tmp;

         scanf("%d%d",&v[i],&tmp);ans+=v[i];

         add(i+m,T,v[i]);

         for(int j=;j<=tmp;j++)

         {

             scanf("%d%d",&t1,&t2);

             add(t1,i+m,t2);

         }

     }

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

     {

         scanf("%d",&t1);

         add(S,i,t1);

     }

     printf("%d\n",ans-dinic());

     return ;

 }