#include <bits/stdc++.h>
#define int long long
using namespace std;
int to_bits(vector<int>& numbers) {
int number = 0;
int cnt = 64;
for (int i = numbers.size()-1;i >= 0;i--) {
// cout << numbers[i] << " ";
while (numbers[i] < cnt) {
cnt--;
number *= 2;
}
// cout << cnt << " " << number << " - ";
number += 1;
}
while (--cnt) {
number *= 2;
}
// cout << "\n";
return number;
}
int target = 0;
pair<int, vector<int>> bf(vector<int>& numbers, vector<int> fk, int index, int number) {
if (index == numbers.size()) {
if (number == target) {
return {0, fk};
} else {
return {+1000000000000, fk};
}
}
if (number == target) {
return {0, fk};
}
fk.push_back(index);
auto ans2 = bf(numbers, fk, index+1, number ^ numbers[index]);
// cout << "1: " << (numbers[index]^number) << "\n";
fk.pop_back();
auto ans1 = bf(numbers, fk, index+1, number);
ans2.first += 1;
return min(ans1, ans2);
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
int n ,m;
cin >> n >> m;
vector<int> results(m);
for (int i = 0;i < m;i++) {
int l;
cin >> l;
vector<int> numbers(l);
for (int& i : numbers) cin >> i;
// for (int i : numbers) {
// cout << i << " ";
// }
// cout << "a\n";
results[i] = to_bits(numbers);
}
for (int i = 1;i <= n;i++) {
target *= 2;
target += 1;
}
auto result = bf(results, {}, 0, 0);
cout << result.first << "\n";
for (int i : result.second) {
cout << i+1 << " ";
}
cout << "\n";
}
