#include<bits/stdc++.h>
using namespace std;
const int Max_S=1e3+10;
const int Size=1e5;
int N,M,Ans;
int S[Max_S],G[Size];
int A[Max_S][Max_S];
int l[Max_S][Max_S],Cnt[Max_S];
struct node{int u,v;};
inline int read(){
	int x=0,f=1;char st=getchar();
	while(st<'0'||st>'9'){if(st=='-') f=-1;st=getchar();}
	while(st>='0'&&st<='9') x=x*10+st-'0',st=getchar();
	return x*f;
}
void Bfs(int num){
	queue<node>q;
	q.push({num,1});
	while(!q.empty()){
		node tmp=q.front();
		q.pop();
		for(int i=1;i<=N;i++){
			if(l[i][tmp.u]==1&&tmp.v+1>G[i]){
				G[i]=tmp.v+1;
				q.push({i,tmp.v+1});
				Ans=max(Ans,G[i]);
			} 
		}
	}
}
int main(){
	N=read();M=read();
	for(int i=1;i<=M;i++){
		S[i]=read(); 
		queue<int>Lower;
		A[i][1]=read();
		for(int j=2;j<=S[i];j++){
			A[i][j]=read();
			for(int k=A[i][j-1]+1;k<A[i][j];k++) Lower.push(k);
		}
		while(!Lower.empty()){
			int j=Lower.front();Lower.pop();
			for(int k=1;k<=S[i];k++){
				if(l[A[i][k]][j]==0){l[A[i][k]][j]=1;Cnt[A[i][k]]++;}
			}
		}
	}
	for(int i=1;i<=N;i++){
		if(Cnt[i]==0){G[i]=1;Bfs(i);}
	}
	cout<<Ans<<endl;
	return 0;
}