#include <iostream>
#include <fstream>
#define MAX_LENGTH 1000000

int result[MAX_LENGTH], a[MAX_LENGTH], b[MAX_LENGTH];
long n, m, len;

using namespace std;

void interclasare(int a[MAX_LENGTH], long n, int b[MAX_LENGTH], long m, int result[MAX_LENGTH], long &length)
{
    long i = 0, j = 0, k;
    length = m + n;
    for(k = 0 ; (i < n) && (j < m) ; k++)
        if(a[i] < b[j])
        {
            result[k] = a[i];
            i++;
        }
        else
        {
            result[k] = b[j];
            j++;
        }
    while(i < n)
    {
        result[k] = a[i];
        i++;
        k++;
    }
    while(j < m)
    {
        result[k] = b[j];
        j++;
        k++;
    }
}

int main()
{
    int k, i = 1;
    long j;
    fstream f("interclasari.in", ios::in);
    fstream g("interclasari.out", ios::out);
    f >> k;
    f >> n;
    for(j = 0 ; j < n ; j++)
        f >> a[j];
    while(i < k)
    {
        f >> m;
        for(j = 0 ; j < m ; j++)
            f >> b[j];
        i++;
        interclasare(a, n, b, m, result, len);
        n = len;
        for(j = 0 ; j < len ; j++)
            a[j] = result[j];
    }
    g << len <<endl;
    for(j = 0 ; j < len ; j++)
        g << result[j] << " ";
    return 0;
}