#include <iostream>
using namespace std;
int Min = 16;
int Max = 0;
bool state[31] = {0};
bool renshi[31][31] = {0};
void getMin(int lower, int already, int all){
	if(already < all){
		if(lower > Max - all + already + 1) return;
		for(int i = lower; i <= Max - all + already + 1; i++){
			state[i] = 1;
			getMin(i+1, already+1, all);
			state[i] = 0;
		}
	}
	else{
		int ban1[16], ban2[16];
		int B1 = 0, B2 = 0;
		for(int i = 1; i <= Max; i++){
			if(state[i]){
				ban1[B1] = i;
				B1++;
			}
			else{
				ban2[B2] = i;
				B2++;
			}
		}
		int tempMax = 0;
		for(int i = 0; i < B1; i++){
			int tM = 0;
			for(int j = 0; j < B1; j++){
				if(!renshi[ban1[i]][ban1[j]]) tM++;
			}
			if(tM>tempMax) tempMax = tM;
		}
		for(int i = 0; i < B2; i++){
			int tM = 0;
			for(int j = 0; j < B2; j++){
				if(!renshi[ban2[i]][ban2[j]]) tM++;
			}
			if(tM>tempMax) tempMax = tM;
		}
		if(tempMax < Min) Min = tempMax;
	}
}
int main() {
	int bianhao;
	while(cin >> bianhao){
		if(bianhao > Max) Max = bianhao;
		int geshu;
		cin >> geshu;
		for(int i = 0; i < geshu; i++){
			int temp;
			cin >> temp;
			renshi[bianhao][temp] = 1;
		}
	}
	for(int i = 1; i <= Max; i++) renshi[i][i] = 1;
	state[1] = 1;
	getMin(2, 1, Max/2);
	if(Max%2 == 1) getMin(2, 1, Max/2+1);
	cout << Min << endl;
	return 0;
}