#include <fstream>
#include <queue>
#include <algorithm>
#include <set>

using namespace std;

ifstream cin("interclasari.in");
ofstream cout("interclasari.out");

const int MAXN = 20;
const int MAXK = 1000000;

int v[1 + MAXK * MAXN];

int main() {
    int n;
    cin >> n;
    int pointer = 0;
    for (int i = 1; i <= n; i++) {
        int k;
        cin >> k;
        for (int i = 1; i <= k; i++) {
            pointer++;
            cin >> v[pointer];
        }
    }
    sort(v + 1, v + pointer + 1);
    cout << pointer << "\n";
    for (int i = 1; i <= pointer; i++)
        cout << v[i] << " ";
    return 0;
}