#include <fstream>

using namespace std;
ifstream cin("balanta.in");
ofstream cout("balanta.out");
int n,m,a[2001],b[2001],i,j,k,z[2001],nr1,nr2,p1,p2;
int main()
{
 cin>>n>>m;
 for(i=1;i<=m;i++)
 {
     cin>>k;
     for(j=1;j<=2*k+1;j++)
        cin>>z[j];

     if(z[2*k+1]==0)
        {
            for(j=1;j<=2*k;j++)
        {a[z[j]]=1;
   b[z[j]]=1;}
        }
     else
        if(z[2*k+1]==1)
     {
         for(j=1;j<=k;j++)
            a[z[j]]=1;
         for(j=k+1;j<=2*k;j++)
            b[z[j]]=1;
     }
     else
     {
       for(j=1;j<=k;j++)
            b[z[j]]=1;
         for(j=k+1;j<=2*k;j++)
            a[z[j]]=1;
     }
 }
  for(i=1;i<=n;i++)
     {
        if(a[i]==0)
        {
            nr1++;
            p1=i;
        }
        if(b[i]==0)
        {
            nr2++;
            p2=i;
        }
     }
     if(nr1==1||nr2==1)
     {
         if(nr1==1)
            cout<<p1;
         else
            cout<<p2;
     }
     else
        cout<<0;
    return 0;

}