#include <fstream>
#include <vector>
#include <algorithm>
#define MAX 20000005
using namespace std;
ifstream fi("interclasari.in");
ofstream fo("interclasari.out");

vector <int> V;
vector <int> :: iterator it;
int k,n,x,i,j;
int main()
{
    fi>>k;
    for (i=1; i<=k; i++)
    {
        fi>>n;
        for (j=1; j<=n; j++)
        {
            fi>>x;
            V.push_back(x);
        }
    }
    sort(V.begin(),V.end());
    fo<<V.size()<<"\n";
    for (it=V.begin(); it!=V.end(); it++)
        fo<<*it<<" ";
    return 0;
}