#include<cstdio>

#include<cstring>

#include<algorithm>

using namespace std;

const int M=;

int read(){

    int ans=,f=,c=getchar();

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

    while(c>=''&&c<=''){ans=ans*+(c-''); c=getchar();}

    return ans*f;

}

int f[M][M],cnt;

int in[M],x,n,m,v,sum[M];

int head,tail,ans=,q[M],num[M];

int main()

{

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

    while(m--){

        v=read(); cnt++;

        for(int i=;i<=v;i++) q[i]=read(),sum[q[i]]=cnt;

        for(int i=q[];i<=q[v];i++)if(sum[i]!=cnt){

            for(int k=;k<=v;k++)

             if(!f[i][q[k]]) f[i][q[k]]=,in[q[k]]++;

        }

    }

    for(int i=;i<=n;i++) if(!in[i]) q[tail++]=i,num[i]++;

    while(head!=tail){

        int x=q[head++]; if(head>M) head=;

        for(int i=;i<=n;i++) if(f[x][i]){

            in[i]--;

            if(!in[i]) {q[tail++]=i; num[i]=num[x]+;}

        }

    }

    for(int i=;i<=n;i++) ans=max(ans,num[i]);

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

    return ;

}