#include <fstream>
#include <stdio.h>
#include <algorithm>
using namespace std;
ifstream f("interclasari.in");
int K,N,v[2000010];

int main()
{
    f>>K;
    for(int i=1; i<=K;i++)
    {
        int n;
        f>>n;
        for(int j=0;j<n;j++)f>>v[N+j];
        N+=n;
    }
    sort(v+1,v+N);
    freopen("interclasari.out", "w", stdout);
    printf("%d\n",N);
    for(int i=0;i<N;i++)printf("%d ",v[i]);
    return 0;
}