1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
#include <iostream>
#include <vector>
#include <set>

using namespace std;

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

    long long k;
    cin >> k;
    long long n1;
    cin >> n1;

    vector<vector<long long>> meetings(k - 1);

    for (long long i = 0; i < k - 1; i++) {
        long long n;
        cin >> n;
        meetings[i].resize(n);
        for (long long j = 0; j < n; j++) {
            cin >> meetings[i][j];
        }
    }
    long long max = 0;
    vector<long long> participants = vector<long long>(k == 1 ? n1 : meetings[k - 2].size());
    for (long long i = k - 2; i >= 0; i--) {
        long long n = meetings[i].size();
        long long used = 0;
        for (long long j = 0; j < n; j++) {
            if (participants[j] == 0) {
                participants[j] = 1;
            }
            used += participants[j];
        }
        if (used > max) {
            max = used;
        }

        // cout << "i = " << i << ", max = " << max << " participants: " << endl;
        // for (long long j = 0; j < participants.size(); j++) {
        //     cout << "  " << j + 1 << ": " << participants[j] << endl;
        // }
        // cout << endl;

        vector<long long> newParticipants = vector<long long>(i == 0 ? n1 : meetings[i - 1].size());
        for (long long j = 0; j < n; j++) {
            if (meetings[i][j] > 0) {
                newParticipants[meetings[i][j] - 1] += participants[j];
            }
        }
        participants = newParticipants;
    }

    long long used = 0;
    for (long long j = 0; j < n1; j++) {
        if (participants[j] == 0) {
            participants[j] = 1;
        }
        used += participants[j];
    }
    if (used > max) {
        max = used;
    }

    // cout << "i = " << -1 << ", max = " << max << " participants: " << endl;
    // for (long long j = 0; j < participants.size(); j++) {
    //     cout << "  " << j + 1 << ": " << participants[j] << endl;
    // }
    // cout << endl;


    cout << max << endl;
}