#include <bits/stdc++.h>

using namespace std;

priority_queue <int> q;

int main()
{
    int n, cnt, i, k, x, pas;
    freopen("interclasari.in", "r", stdin);
    scanf("%d", &k);
    cnt = 0;
    for (pas = 1; pas <= k; ++pas)
    {
        scanf("%d", &n);
        cnt += n;
        for (i = 1; i <= n; ++ i)
        {
            scanf("%d", &x);
            q.push(-x);
        }
    }

    freopen("interclasari.out", "w", stdout);
    printf("%d\n", cnt);
    while (cnt > 0)
    {
        printf("%d ", -q.top());
        q.pop();
        cnt--;
    }
    printf("\n");
    return 0;
}