#include<bits/stdc++.h>

using namespace std;
ifstream fin("interclasari.in");
ofstream fout("interclasari.out");
vector <int> a;
int k;
int main()
{
    int i,j,m,x;
    fin>>k;
    for(i=1;i<=k;i++)
    {
        fin>>m;
        for(j=1;j<=m;j++)
        {
            fin>>x;
            a.push_back(x);
        }
    }
    x = a.size();
    fout<<x<<"\n";
    sort(a.begin(),a.end());
    for(i=0;i<x;i++) fout<<a[i]<<" ";



    fout.close();
    return 0;
}