#include <iostream>
#include <vector>

#define REP(x,n) for(int x=0;x<(n);++x)

using namespace std;

const int MAX_N = 500000;
struct Meeting {
    int origin;
    int people;
};

vector<Meeting> meetings[MAX_N];


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int k,n;
    cin >> k >> n;
    if (k == 1) {
        cout << n;
        return 0;
    }
    meetings[1].resize(n, Meeting{0,0});
    int ni;
    for (int i = 2; i <= k; i++) {
        auto& dailyMeetings = meetings[i];
        cin >> ni;
        dailyMeetings.resize(ni, Meeting{0,0});
        REP(x,ni) {
            cin >> dailyMeetings[x].origin;
        }
    }

    int bestResult = 0;
    for (int i = k; i >= 0; i--) {
        int currentResult = 0;
        for (Meeting& m : meetings[i]) {
            // cerr << " (" << m.origin << "," << m.people << ")";
            if (m.people == 0) {
                m.people = 1;
            }

            if (m.origin != 0 && i) {
                meetings[i-1][m.origin-1].people += m.people;
            }
            currentResult += m.people;
        }
        bestResult = max(bestResult, currentResult);
        // cerr << endl << "after " << i << " " << currentResult << " / " << bestResult << endl;
    }

    cout << bestResult;
    return 0;
}