#include<algorithm>

 #include<cstdio>

 #include<cmath>

 #include<cstring>

 #include<iostream>

 #define inf 0x7fffffff

 struct edge{

     int u,v;

 }e[];

 int tot,go[],first[],next[],flow[];

 int op[],cnt[],dis[],n,m,mx[],all,ru[];

 int id[][],w[][],S,T,nodes,pd[],c[];

 int read(){

     int t=,f=;char ch=getchar();

     while (ch<''||ch>'') {if (ch=='-') f=-;ch=getchar();}

     while (''<=ch&&ch<=''){t=t*+ch-'';ch=getchar();}

     return t*f;

 }

 void insert(int x,int y,int z){

     tot++;

     go[tot]=y;

     next[tot]=first[x];

     first[x]=tot;

     flow[tot]=z;

 }

 void add(int x,int y,int z){

     insert(x,y,z);op[tot]=tot+;

     insert(y,x,);op[tot]=tot-;

 }

 int dfs(int x,int f){

     if (x==T) return f;

     int sum=,mn=nodes;

     for (int i=first[x];i;i=next[i]){

         int pur=go[i];

         if (flow[i]&&dis[pur]+==dis[x]){

             int save=dfs(pur,std::min(f-sum,flow[i]));

             sum+=save;

             flow[i]-=save;

             flow[op[i]]+=save;

             if (sum==f||dis[S]>=nodes) return sum;

         }

         if (flow[i]) mn=std::min(mn,dis[pur]);

     }

     if (sum==){

         cnt[dis[x]]--;

         if (cnt[dis[x]]==){

             dis[S]=nodes;

         }else{

             dis[x]=mn+;

             cnt[dis[x]]++;

         }

     }

     return sum;

 }

 int main(){

     n=read();m=read();

     S=;nodes=;

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

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

       id[i][j]=nodes++;

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

      for (int j=;j<=m;j++){

         w[i][j]=read();

         int num=read();

         for (int k=;k<=num;k++){

             int x=read(),y=read();

             x++;y++;

             e[++all].u=id[i][j],e[all].v=id[x][y],ru[e[all].v]++;

         }

     }

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

      for (int j=m;j>;j--)

       e[++all].u=id[i][j],e[all].v=id[i][j-],ru[id[i][j-]]++;

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

      insert(e[i].u,e[i].v,);

     T=nodes;nodes++;

     int top=;

     for (int i=;i<=nodes-;i++)

      if (ru[i]==)

       pd[i]=,c[++top]=i;

     while (top>){

         int now=c[top--];

         for (int i=first[now];i;i=next[i]){

             int pur=go[i];

             ru[pur]--;

             if (ru[pur]==){

                 pd[pur]=;

                 c[++top]=pur;

             }

         }

     }

     tot=;

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

       first[i]=;

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

      if (pd[e[i].u]&&pd[e[i].v])

       add(e[i].u,e[i].v,inf);

     int sum=;  all=;

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

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

       if (pd[id[i][j]]){

             if (w[i][j]>) add(id[i][j],T,w[i][j]),sum+=w[i][j];

             else

             if (w[i][j]<) add(S,id[i][j],-w[i][j]);

             all++;

       }

     nodes=all;

     int ans=;

     while (dis[S]<nodes) ans+=dfs(S,inf);

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

 }