#include <bits/stdc++.h>
using namespace std;
int n, m;
vector<int> spell_masks;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
spell_masks.resize(m);
for (int i = 0; i < m; ++i) {
int q;
cin >> q;
int mask = 0;
for (int j = 0; j < q; ++j) {
int a;
cin >> a;
mask |= (1 << (a - 1));
}
spell_masks[i] = mask;
}
int goal = (1 << n) - 1;
queue<int> q;
map<int, vector<int>> visited;
q.push(0);
visited[0] = {};
while (!q.empty()) {
int state = q.front();
q.pop();
vector<int> path = visited[state];
if (state == goal) {
cout << path.size() << "\n";
for (int idx : path) cout << idx << " ";
cout << "\n";
return 0;
}
for (int i = 0; i < m; ++i) {
int new_state = state ^ spell_masks[i];
vector<int> new_path = path;
new_path.push_back(i + 1);
if (!visited.count(new_state) || visited[new_state] > new_path) {
visited[new_state] = new_path;
q.push(new_state);
}
}
}
cout << -1 << "\n"; // Çözüm yoksa
return 0;
}
