#include <bits/stdc++.h>
#define int long long
#define debug(x) cout << #x << " = " << x << endl;
using namespace std;
const long long N = 2e5 + 5;
const long long M = (1ll << 25) + 5;
int a[N];
int dp[M];
void solve()
{
int n, m;
cin >> n >> m;
int sz, e;
// vi[a];
for (int j = 0; j < m; j++)
{
cin >> sz;
int mask = 0;
for (int i = 0; i < sz; i++)
{
cin >> e;
a[j] |= 1ll << (e - 1);
}
}
// for (int i = 0; i < m; i++)
// {
// cout << a[i] << ' ';
// }
// cout << endl;
// int m = __lg(m)+1;
vector<int> answers;
dp[0] = 0;
int ans = 0;
for (int i = 1; i < (1ll << (m)); i++)
{
int j = (i - 1) & i;
int subset = i ^ j;
dp[i] = dp[j] ^ a[__lg(subset)];
// debug(i);
// debug(j);
// debug(subset);
// debug(dp[j]);
// debug(a[subset-1]);
// debug(dp[i]);
// cout << dp[j] << ' '<< a[subset-1] << endl;
// cout << endl;
// cout << i << ' '<<dp[i] << endl;
// cout << endl;
if ((dp[i] ^ ((1ll << (n)) - 1)) == 0)
{
answers.push_back(i);
// break;
}
}
sort(answers.begin(), answers.end(), [&](const int a, const int b) -> bool
{
int ca = __builtin_popcountll(a);
int cb = __builtin_popcountll(b);
if (ca == cb)
{
int mask;
for (int i = 0; i < m;i++)
{
mask = 1ll << i;
if (((mask & a)) && ((mask & b) == 0))
return 1;
if (((mask & b)) && ((mask & a) == 0))
return 0;
}
}
return (ca < cb); });
ans = answers[0];
int mask;
vector<int> answer;
for (int i = 0; i < m; i++)
{
mask = 1ll << i;
if (mask & ans)
{
answer.push_back(i);
}
}
cout << answer.size() << endl;
for (auto i : answer)
cout << i + 1 << ' ';
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
int t = 1;
// cin >> t;
for (int i = 1; i <= t; i++)
{
// cout << "Case #" << i << ':' << ' ';
solve();
cout << endl;
}
return 0;
}
