#include <fstream>
#include <algorithm>
#include <queue>
#include <vector>

using namespace std;

ifstream fin("interclasari.in");
ofstream fout("interclasari.out");

int n, k, cnt;
priority_queue<int> q;

int main() {
    fin >> k;
    for (int i = 0; i < k; ++ i) {
        fin >> n;
        for (int j = 0; j < n; ++ j) {
            int temp;
            fin >> temp;
            ++ cnt;
            q.push(-temp);
        }
    }
    fin.close();
    fout << cnt << "\n";
    while (!q.empty()) {
        fout << -q.top() << " ";
        q.pop();
    }
    fout << "\n";
    fout.close();
    return 0;
}