#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;
}