/*************************************************************************

     > File Name: uva-315.network.cpp

     > Author: CruelKing

     > Mail: 2016586625@qq.com

     > Created Time: 2019年09月06日 星期五 17时15分07秒

     本题思路:就是求图中有多少个割点

  ************************************************************************/

 #include <cstdio>

 #include <iostream>

 #include <sstream>

 #include <cstring>

 #include <string>

 using namespace std;

 const int maxn =  + , maxm = maxn * maxn + ;

 int tot, head[maxn];

 struct Edge {

     int to, next;

 } edge[maxm];

 void init() {

     memset(head, -, sizeof head);

     tot = ;

 }

 void addedge(int u, int v) {

     edge[tot] = (Edge) {v, head[u]}; head[u] = tot ++;

     edge[tot] = (Edge) {u, head[v]}; head[v] = tot ++;

 }    

 int n;

 string str;

 int dfn[maxn], low[maxn], stack[maxn];

 bool cut[maxn], instack[maxn];

 int Index, top, cut_num;

 void tarjan(int u, int pre) {

     dfn[u] = low[u] = ++ Index;

     instack[u] = true;

     stack[top ++] = u;

     int son = ;

     for(int i = head[u]; ~i; i = edge[i].next) {

         int v = edge[i].to;

         if(!dfn[v]) {

             son ++;

             tarjan(v, u);

             if(low[u] > low[v]) low[u] = low[v];

             if(pre != u && low[v] >= dfn[u]) {

                 cut[u] = true;

             }

         } else if(low[u] > dfn[v]) low[u] = dfn[v];

     }

     if(u == pre && son > ) {

         cut[u] = true;

     }

     instack[u] = false;

     top --;

 }

 void solve() {

     memset(dfn, , sizeof dfn);

     memset(low, , sizeof low);

     memset(cut, false, sizeof cut);

     Index = top = cut_num = ;

     for(int i = ; i <= n; i ++) {

         if(!dfn[i]) tarjan(i, i);

     }

     for(int i = ; i <= n; i ++) if(cut[i]) cut_num ++;

     printf("%d\n", cut_num);

 }

 int main() {

     int u, v;

     while(~scanf("%d", &n) && n) {

         init();

         while(scanf("%d", &u)) {

             if(u == ) break;

             getline(cin, str);

             stringstream ss;

             ss << str;

             while(ss >> v) addedge(u, v);

         }

         solve();

     }

     return ;

 }