#include <fstream>
#include <list>
using namespace std;

list<int> l[21];
list<int>::iterator it;


int nr,i,minim,n,j,k,x;

int main()
{
    FILE *f = fopen("interclasari.in","r");
    FILE *g = fopen("interclasari.out","w");
    fscanf(f, "%d", &k);
    for(i=1;i<=k;i++)
    {
        fscanf(f, "%d", &n);
        nr+=n;
        for(j=1;j<=n;j++)
        {
            fscanf(f,"%d",&x);
            l[i].push_back(x);
        }
    }

    fprintf(g,"%d\n",nr);
    nr=1;
    while(nr)
    {
        nr=0;minim=-1;
        for(i=1;i<=k;i++)
        if((l[i].front()<minim || minim==-1) && !l[i].empty())
            {
                minim=l[i].front();
                nr=i;
            }
        if(nr)
        {
            fprintf(g,"%d ", minim);
            l[nr].pop_front();
        }
    }
    fprintf(g,"\n");
    return 0;
}