#include<bits/stdc++.h>
using namespace std;
ifstream f("interclasari.in");
ofstream g("interclasari.out");
int k,i,j,x,v[20000001],a,n;
int main()
{
    for(f>>k,i=1;i<=k;++i)
        for(f>>n,j=1;j<=n;++j)
            f>>x,v[++a]=x;
    for(sort(v+1,v+a+1),g<<a<<'\n',i=1;i<=a;++i)
        g<<v[i]<<' ';
    return 0;
}