#include <fstream>
#include <vector>

#define In "interclasari.in"
#define Out "interclasari.out"
#define Inf 0x3f3f3f3f

using namespace std;

vector<int>::iterator it[20];
vector<int>a[20];
int T,S;

inline void Citire()
{
    int i,j,n;
    ifstream f(In);
    f >> T;
    for(i = 0;i < T;i++)
    {
        f >> n;
        S += n;
        a[i].resize(n);
        for(j = 0;j < n;j++)
            f >> a[i][j];
        it[i] = a[i].begin();
    }
}

inline void Rezolvare()
{
    int i,j , minm, poz;
    ofstream g(Out);
    g<<S<<"\n";
    for(i = 0;i < S;i++)
    {
        minm = Inf;
        for(j = 0;j < T;j++)
            if(it[j]!=a[j].end() && (*it[j])<minm)
            {
                minm = *it[j];
                poz = j;
            }
        it[poz]++;
        g<<minm<<" ";
    }
    g<<"\n";
    g.close();
}

int main()
{
    Citire();
    Rezolvare();
    return 0;
}