#include <stdio.h>
#include <string.h>

#define Nmax 1025

int A[Nmax],B[Nmax],i,ok,okk,poz,poz1,N,M,K,r,r1,j,k,x,oh,S[Nmax],D[Nmax],frecv[Nmax];


int main()
{
    freopen("balanta.in","r",stdin);
    scanf("%d %d", &N,&M);
    freopen("balanta.out","w",stdout);
    for (i=1;i<=N;++i)
          {
             S[i]=0;
             D[i]=0;
          }   
    while (M--)
          {
              scanf("%d",&K);
              for (j=1;j<=K;++j)
                   scanf("%d", &A[j]);
              for (j=1;j<=K;++j)
                   scanf("%d", &B[j]);
              scanf("%d", &r);
               if (r!=0)
                   {
                   for (j=1;j<=K;++j)
                           {
                              S[A[j]]=A[j];
                              D[B[j]]=B[j];
                            }
                    } 
        }
      memset(frecv,0,sizeof(frecv));  
      for (i=1;i<=N;++i)
            {
              frecv[S[i]]++;
              frecv[D[i]]++;
            }
     ok=1;
     for (i=1;i<=N;++i)
           if (frecv[i]>1)
               {
                  printf("%d", i);
                  ok=0;
                  break;
                }
     if (ok) printf("0");             
     return 0;
}