#include<bits/stdc++.h>
using namespace std;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n , m;
cin >> n >> m;
long long M = (1LL << n) - 1;
long long v[m];
for(int i = 0;i < m;i ++){
int x;
cin >> x;
v[i] = 0;
while(x--){
int y;
cin >> y;
--y;
v[i] |= (1LL << y);
}
}
vector<pair<long long , int>> u;
u.emplace_back(make_pair(0LL , 0));
for(int i = 0;i < m;i ++){
vector<pair<long long , int>> e;
for(auto [x , mask] : u){
e.emplace_back(make_pair(x ^ v[i] , mask | (1LL << i)));
}
for(auto [x , mask] : e){
u.emplace_back(make_pair(x , mask));
}
}
int best_mask = (1 << m) - 1;
for(auto [x , mask] : u){
if(x != M){
continue;
}
if(__builtin_popcount(mask) < __builtin_popcount(best_mask)){
best_mask = mask;
}else if(__builtin_popcount(mask) == __builtin_popcount(best_mask)){
int v = mask ^ best_mask;
if(mask >> (__lg(v & -v)) & 1){
best_mask = mask;
}
}
}
cout << __builtin_popcount(best_mask) << endl;
for(int i = 0;i < m;i ++){
if(best_mask >> i & 1){
cout << i + 1 << " ";
}
}
cout << endl;
}
