#include <bits/stdc++.h>
using namespace std;

int main()
{
    freopen("interclasari.in", "r", stdin);
    freopen("interclasari.out", "w", stdout);
    priority_queue <int> q;
    int n, s=0, i, k, x;
    scanf("%d", &k);
    while(k--)
    {
        scanf("%d", &n);
        s=s+n;
        for(i=1; i<=n; i++)
        {
            scanf("%d", &x);
            q.push(-x);
        }
    }
    printf("%d\n", s);
    while (s)
    {
        printf("%d ", -q.top());
        q.pop();
        s--;
    }
    fclose(stdin);
    fclose(stdout);
    return 0;
}