#8 #9 RE 求助

#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;
}