#include <fstream>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <climits>

#include <ctype.h>

#define MAX 20000000


using namespace std;


//ifstream f("in.in");
//ofstream g("out.out");

ifstream f("interclasari.in");
ofstream g("interclasari.out");

int v[MAX +1],n,m,k=0;

int main(){

    f>>n;
    for(int i=1;i<=n;i++){
        f>>m;

        for(int j=1;j<=m;j++){
            f>>v[k+j];
        }

        k+=m;
    }
    sort(v+1,v+k+1);
    g<<k<<'\n';
    for(int i=1;i<=k;i++){
        g<<v[i]<<" ";
    }

    f.close();
    g.close();
    return 0;
}