#include <bits/stdc++.h>

using namespace std;

class cmp
{
public:
    bool operator () (int a, int b)
    {
        return a > b;
    }
};

int k, n, nrfin;
priority_queue <int, vector <int>, cmp> Heap;

int main()
{
    freopen("interclasari.in", "r", stdin);
    freopen("interclasari.out", "w", stdout);
    scanf("%d", &k);
    for (int i = 1; i <= k; i++)
    {
        scanf("%d", &n);
        nrfin += n;
        for (int i1 = 1, add; i1 <= n; i1++)
            scanf("%d", &add), Heap.push(add);
    }
    printf("%d\n", nrfin);
    for (int i = 1; i <= nrfin; i++)
    printf("%d ", Heap.top()), Heap.pop();
    return 0;
}