#include <bits/stdc++.h>

using namespace std;
const int N = 2010, M = 1000010;
int n, m;
int d[N];
int st[N];

int e[M], h[N], idx, w[M], ne[M];
void add(int a, int b, int c) {
    e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
}

int dfs(int u) {
    if (~d[u]) return d[u]; // 记忆化搜索
    d[u] = 1;               // 最少是一级
    for (int i = h[u]; ~i; i = ne[i]) {
        int j = e[i];
        d[u] = max(d[u], dfs(j) + w[i]);
    }
    return d[u];
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("456.in", "r", stdin);
#endif

    ios::sync_with_stdio(false), cin.tie(0);
    cin >> n >> m;

    memset(h, -1, sizeof h);
    for (int i = 1; i <= m; i++) {
        memset(st, 0, sizeof st);

        int k;
        cin >> k;
        int S = n, T = 1;
        for (int j = 1; j <= k; j++) {
            int x;
            cin >> x;
            S = min(S, x);
            T = max(T, x);
            st[x] = 1;
        }

        for (int j = S; j <= T; j++)
            if (st[j])
                add(n + i, j, 1);
            else
                add(j, n + i, 0);
    }

    int res = 0;
    memset(d, -1, sizeof d);
    for (int i = 1; i <= n; i++) res = max(res, dfs(i));
    printf("%d\n", res);
    return 0;
}