#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e3 + 10;
int te, tb, degree[MAXN], n, m, d[MAXN], ans = INT_MIN;
bool v[MAXN];
vector<int> G[MAXN];
void bfs() {
	queue<int> q;
	for (int i = 1; i <= n; i++) {
		if (!degree[i]) {
			q.push(i);
			d[i] = 1;
		}
	}
	while(q.size()) {
		int x = q.front();
		q.pop();
		for (int i = 0; i < G[x].size(); i++) {
			int y = G[x][i];
			if (degree[y]) degree[y]--;
			if (!degree[y]) {
				q.push(y);
				d[y] = d[x] + 1;
				ans = max(ans, d[y]);
			}
		}
	}
}
int main() {
	scanf("%d%d", &n, &m);
	for (int i = 1; i <= m; i++) {
		int t;
		te = 0;
		tb = 0;
		scanf("%d", &t);
		memset(v, false, sizeof(v));
		for (int j = 1; j <= t; j++) {
			int k;
			scanf("%d", &k);
			v[k] = true;
			if (j == t)
				te = k;
			if (j == 1)
				tb = k;
		}
		for (int l = tb; l <= te; l++) {
			if (!v[l]) {
				for (int ll = tb; ll <= te; ll++) {
					if (v[ll]) {
						G[ll].push_back(l);
						degree[l]++;
					}
				}
			}
		}
	}
	bfs();
	printf("%d", ans);
	return 0;
}