#pragma GCC optimize ("O3,unroll-loops")
//#pragma GCC target ("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
//#define int long long
using namespace std;
vector<vector<char>> sp; // boyumu aşan soruya giriştim ya 100le çıkıp sonlarda takılcaz ya da soruyu yapıp top 5 yapcaz (kesin debug atamıcam)
vector<char> cur, tgt;
vector<int> cmb;
bool ok;
void dfs(int st, int need, int n, int m){ // 800 ms ne oha
if(ok) return;
if(need==0){
for(int i=0; i<n; i++) if(cur[i]==0) return;
cout<<cmb.size()<<"\n";
for(size_t i=0; i<cmb.size(); i++){ if(i) cout<<" "; cout<<cmb[i]; } cout<<"\n";
ok=true; return;
}
for(int i=st; i<=m-need; i++){
for(int p=0; p<n; p++) cur[p]^=sp[i][p];
cmb.push_back(i+1);
dfs(i+1, need-1, n, m);
if(ok) return;
cmb.pop_back();
for(int p=0; p<n; p++) cur[p]^=sp[i][p];
}
}
int32_t main(){ // galiba debug attım (caresizim, yardım gönderin)
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int n, m; cin>>n>>m;
sp.assign(m, vector<char>(n, 0));
cur.assign(n, 0);
tgt.assign(n, 1);
for(int i=0; i<m; i++){
int q; cin>>q;
for(int j=0; j<q; j++){
int v; cin>>v; v--;
sp[i][v]=1;
}
}
cmb.clear();
ok=false;
for(int t=1; t<=m && !ok; t++) dfs(0, t, n, m);
return 0;
}
