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#include <bits/stdc++.h>
using namespace std;

typedef long long int LL;

const int MAX_K = 500005;

int k, ni, a, res, curr;
vector<pair<int, int>> prevs[MAX_K];
set<pair<int, int>> used;
vector<pair<int, int>> points;

bool comp(const pair<int, int>& p1, const pair<int, int>& p2)
{
    if(p1.first == p2.first)
    {
        return p1.second > p2.second;
    }

    return p1.first < p2.first;
}

int main()
{
    ios::sync_with_stdio(0);

    cin >> k >> ni;
    prevs[0] = vector<pair<int, int>>(ni, make_pair(-1, -1));

    for(int i = 1; i < k; ++i)
    {
        cin >> ni;
        for(int j = 0; j < ni; ++j)
        {
            cin >> a;
            --a;

            if(a == -1)
            {
                prevs[i].push_back(make_pair(-1, -1));
            }
            else
            {
                if(prevs[i-1][a].first == -1)
                {
                    prevs[i].push_back(make_pair(i-1, a));
                }
                else
                {
                    prevs[i].push_back(prevs[i-1][a]);
                    used.insert(prevs[i-1][a]);
                }

                used.insert(make_pair(i-1, a));
            }

            //cout << "i: " << i << ", j: " << j << ", prevs[i][j]: (" << prevs[i][j].first << ", " << prevs[i][j].first << ")" << endl;
        }
    }

    for(int i = k-1; i >= 0; --i)
    {
        for(int j = 0; j < prevs[i].size(); ++j)
        {
            pair<int, int> event = make_pair(i, j);

            if(used.find(event) != used.cend())
            {
                continue;
            }

            //cout << "processing [" << i << "; " << j << "]" << endl;

            if(prevs[i][j].first == -1)
            {
                points.push_back(make_pair(i, 1));
                points.push_back(make_pair(i, -1));

                //cout << "inserting [" << i << "; " << i << "]" << endl;
                //cout << "--------" << endl;

                continue;
            }

            int endDay = i, startDay = -1;
            int d = i, idx = j;
            while(prevs[d][idx].first != -1)
            {
                //cout << "d: " << d << ", idx: " << idx << ", prevs[d][idx]: (" << prevs[d][idx].first << ", " << prevs[d][idx].second << ")" << endl;

                int newD = prevs[d][idx].first;
                idx = prevs[d][idx].second;
                d = newD;
                startDay = d;

                used.insert(make_pair(d, idx));
            }

            points.push_back(make_pair(startDay, 1));
            points.push_back(make_pair(endDay, -1));

            //cout << "inserting [" << startDay << "; " << endDay << "]" << endl;
            //cout << "--------" << endl;
        }
    }

    sort(points.begin(), points.end(), comp);
    for(const pair<int, int>& p : points)
    {
        if(p.second == 1)
        {
            ++curr;
            if(curr > res)
            {
                res = curr;
            }
        }
        else
        {
            --curr;
        }
    }

    cout << res << endl;

    return 0;

}