#include<iostream>
#include<cstdio>
#include<cstring>
#define maxx   10000000
using namespace std;
int read()
{
   int f=1,x=0;
   char ch;
   ch=getchar();while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
   while(ch>=‘0‘&&ch<=‘9‘){x=(x<<1)+(x<<3)+ch-‘0‘;ch=getchar();}
   return x*f;
}
int sum=0;
int st,ed;
int n,m;
int tot=0;
int vis[10000];
int level[10000];
int map[1000][1000];
int ww[600][500];
int c[100000];
int v[100000];
struct {int flow,next,y;}e[1000000];
int len=0;
int re[1000000];
int q[1000000],le[1000000],head,tail,lin[10000000];
void init(int x,int y,int flow)
{
   vis[y]++;
   e[++len].flow=flow;e[len].y=y;e[len].next=lin[x];lin[x]=len;re[len]=len+1;
   e[++len].flow=0;e[len].y=x;e[len].next=lin[y];lin[y]=len;re[len]=len-1;
   return ;
}
void initx()
{	
	st=++tot;
    n=read();m=read();	
    for(int i=0;i<=n-1;i++)for(int u=0;u<=m-1;u++){map[i][u]=++tot;if(u-1>=0)init(map[i][u],map[i][u-1],maxx);}
    ed=++tot;
    for(int i=0;i<=n-1;i++)
    {
		for(int u=0;u<=m-1;u++)
		{
			v[map[i][u]]=read();
			int w=read();
			for(int z=1;z<=w;z++)
			{
				int x,y;
				x=read();
				y=read();
				init(map[i][u],map[x][y],maxx);
			}
		}
	}
}
int f[1000000];
void topsort()
{
	head=0;tail=0;
	for(int i=map[0][0];i<=map[n-1][m-1];i++)
		if(vis[i]==0)q[++tail]=i;
   while(head++<tail)
   {
      int x=q[head];
      for(int i=lin[x];i;i=e[i].next)
      {
		 if(e[i].flow<=0)continue;
		 int y=e[i].y;
		 vis[y]--;
		 if(vis[y]==0)q[++tail]=y;
    }
   }
   for(int i=1;i<=tail;i++)
   {
	   f[q[i]]=1;
	   if(v[q[i]]>=0){init(q[i],ed,v[q[i]]),sum+=v[q[i]];}
	   else init(st,q[i],-v[q[i]]);
   }
}
bool makelevel()
{
   f[st]=1;
   f[ed]=1;
   memset(level,-1,sizeof(level));
   head=0;tail=1;
   q[1]=st;level[st]=0;
   while(head++<tail)
   {
	int x=q[head];
	for(int i=lin[x];i;i=e[i].next)
	{
		int y=e[i].y;
		if(e[i].flow<=0)continue;
		if(f[y]==0)continue;
		if(level[y]==-1)
		{
			level[y]=level[x]+1;
			q[++tail]=y;
		}
	}
   }
   //cout<<"s";
   return level[ed]!=-1;
}
int maxlow(int x,int flow)
{
   if(x==ed)return flow;
   int maax=0;
   int d;
    for(int i=lin[x];i&&maax<flow;i=e[i].next)
    {
		int y=e[i].y;
		if(f[y]==0)continue;
		if(e[i].flow<=0)continue;
		if(level[y]!=level[x]+1)continue;
		if(d=maxlow(y,min(flow-maax,e[i].flow)))
		{
			maax+=d;
			e[i].flow-=d;
			e[re[i]].flow+=d;
			
		}
	}
   if(maax==0)level[x]=-1;
   return maax;
}
int ans=0;
void dinic()
{
   int d;
   while(makelevel())
      while(d=maxlow(st,maxx))
      {
		ans+=d;
      }
}
int main()
{
   initx();
   topsort();
   memset(q,0,sizeof(q));
   dinic();
   cout<<sum-ans<<endl;
   return 0;
}