#include <iostream>

#include <vector>

#include <string>

#include <sstream>

using namespace std;

vector< vector<int> > edge;

vector<int> dfn, low;

int result, dep;

void dfs(int cur, int par)

{

	bool cut = false;

	int child = 0;

	dfn[cur] = low[cur] = ++dep;

	for (auto& i : edge[cur]) {

		if (!dfn[i]) {

			++child;

			dfs(i, cur);

			low[cur] = min(low[cur], low[i]);

			if (low[i] >= dfn[cur]) cut = true;

		}

		else if (i != par) low[cur] = min(low[cur], dfn[i]);

	}

	if ((child >= 2 || par != -1) && cut) ++result;

}

int main()

{

	ios::sync_with_stdio(false);

	cin.tie(nullptr);

	cout.tie(nullptr);

	int N;	

	while (cin >> N && N) {

		cin.ignore();

		result = 0, dep = 0;

		edge.assign(N + 1, vector<int>());

		dfn.assign(N + 1, 0);

		low.assign(N + 1, 0);

		string str;

		while (getline(cin, str)) {

			stringstream ss(str);

			int u, v;

			ss >> u;

			if (!u) break;

			while (ss >> v) edge[v].emplace_back(u), edge[u].emplace_back(v);

		}

		dfs(1, -1);

		cout << result << "\n";

	}

	return 0;

}