#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
vector<int> v;
int n, x, k;
int main () {
    ifstream fin ("interclasari.in");
    ofstream fout("interclasari.out");

    fin>>n;
    for (int i=1;i<=n;i++) {
        fin>>x;
        for (int j=1;j<=x;j++) {
            fin>>k;
            v.push_back(k);
        }
    }

    sort(v.begin(), v.end());
    fout<<v.size()<<"\n";
    for (int i=0;i<v.size();i++)
        fout<<v[i]<<" ";
    return 0;
}