// #include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <map>
#include <vector>
#include <iomanip>
#include <string>
#include <queue>
#include <set>
#include <deque>
#include <numeric>
#include <stack>
#include <chrono>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
void fast_io() {
// freopen("", "r", stdin);
// freopen("", "w", stdout);
ios::sync_with_stdio(0);
cin.tie();
cout.tie();
cout << setprecision(9);
}
#define int long long
#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define fi first
#define se second
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
void solve() {
int n, m; cin >> n >> m;
int a[m] = {};
for (int i = 0; i < m; i++){
int s; cin >> s;
while (s--){
int x; cin >> x;
x--;
a[i] += (1ll << x);
}
}
vector<int> ans;
for (int i = 0; i <= m; i++) ans.push_back(m);
for (int i = 0; i < (1ll << m); i++){
int cur = 0;
vector<int> T;
for (int j = 0; j < m; j++){
if (((i >> j) & 1)){
T.push_back(j);
cur ^= a[j];
}
}
if (cur == ((1ll << n) - 1)){
swap(T, ans);
break;
}
}
cout << ans.size() << endl;
for (auto i : ans) cout << i + 1 << ' ';
cout << endl;
// for (auto i : a) cout << i << ' ';
// cout << endl;
}
signed main() {
fast_io();
srand(chrono::steady_clock::now().time_since_epoch().count());
int tc = 1;
// cin >> tc;
while (tc--) solve();
return 0;
}
