#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>

using namespace std;

const int N = 2005, M = 2000005;

int n, m;
int h[N], e[M], ne[M], w[M], idx;
int d[N], q[N], dist[N];
bool st[N];

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

void topsort() {

    int hh = 0, tt = -1;

    for (int i = 1; i <= n + m;i ++ ){
        if (!d[i]) q[ ++ tt] = i;
    }

    while (hh <= tt) {
        int t = q[hh ++ ];
        for (int i = h[t];~i;i = ne[i]) {
            int j = e[i];
            if ( -- d[j] == 0) q[ ++ tt] = j;
        }
    }
}

int main() {

    scanf("%d%d", &n, &m);
    memset(h, -1, sizeof h);

    for (int i = 1;i <= m;i ++ ) {

        memset(st, 0, sizeof st);
        int start = n, end = 1;
        int k; scanf("%d", &k);

        for (int j = 1;j <= k;j ++ ){
            int stop; scanf("%d", &stop);
            start = min(start, stop);
            end = max(end, stop);
            st[stop] = true;
        }

        int ver = n + i;
        for (int i = start;i <= end;i ++ ) {
            if(st[i]) add(ver, i, 1);
            else add(i, ver, 0);
        }
    }

    topsort();

    for (int i = 1;i <= n;i ++ ) dist[i] = 1;
    for (int i = 0;i < n + m;i ++ ){
        int t = q[i];
        for (int j = h[t];~j;j = ne[j]){
            int k = e[j];
            if (dist[k] < dist[t] + w[j]) dist[k] = dist[t] + w[j];
        }
    }

    int res = 0;
    for (int i = 1;i <= n;i ++ ) res = max(res, dist[i]);
    printf("%d", res);
    return 0;
}