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

const int maxN = 500002;

int k;
vector <int> meetings[maxN];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n1;
    cin >> k >> n1;

    for (int j = 0; j < n1; j++) {
        meetings[1].push_back(0);
    }

    for (int i = 2; i <= k; i++) {
        int ni;
        cin >> ni;
        for (int j = 1; j <= ni; j++) {
            int a;
            cin >> a;
            meetings[i].push_back(a);
        }
    }

    int maxi = 0;
    unordered_map<int, int> continuations;
    for (int i = k; i >= 1; i--) {
        int min_people = 0;
        for (int j = 1; j <= (int)meetings[i].size(); j++) {
            min_people += max(1, continuations[j]);
        }
        maxi = max(maxi, min_people);

        unordered_map<int, int> new_continuations;
        for (int j = 1; j <= (int)meetings[i].size(); j++) {
            if (meetings[i][j - 1] > 0) {
                new_continuations[meetings[i][j - 1]] += max(1, continuations[j]);
            }
        }

        continuations = new_continuations;
    }

    cout << maxi << endl;
}