#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>

using namespace std;

int n, k, cnt;
priority_queue<int> q;

int main() {
    freopen("interclasari.in", "r", stdin);
    freopen("interclasari.out", "w", stdout);
    scanf("%d", &k);;
    for (int i = 0; i < k; ++ i) {
        scanf("%d", &n);
        for (int j = 0; j < n; ++ j) {
            int temp;
            scanf("%d", &temp);
            ++ cnt;
            q.push(-temp);
        }
    }
    printf("%d\n", cnt);
    while (!q.empty()) {
        printf("%d ", -q.top());
        q.pop();
    }
    printf("\n");
    return 0;
}