1 #include<iostream>
2 using namespace std;
3 #define black 2
4 #define white 0
5 #define gray 1
6 bool map[101][101];
7 int n;//表示節(jié)點(diǎn)個數(shù)
8 int color[101],D[101];
9 int root=1;//頭節(jié)點(diǎn)
10 int ancestor[101];
11 int cnt;
12 int tme=0;
13 int A[101];
14 bool cut[101];
15 void dfs(int k,int father,int dep)
16 {
17 int tot;
18 color[k]=gray;
19 D[k]=dep;
20 ancestor[k]=dep;
21 tot=0;//表示頂點(diǎn)k的兒子的數(shù)量
22 for(int i=1;i<=n;++i)
23 {
24 if(map[i][k]&&i!=father&&color[i]==gray)
25 ancestor[k]=min(ancestor[k],D[i]);
26 if(map[i][k]&&color[i]==white)
27 {
28 dfs(i,k,dep+1);
29 tot++;
30 ancestor[k]=min(ancestor[k],ancestor[i]);
31 //根節(jié)點(diǎn)
32 if(k==root&&tot>1)cut[k]=1;
33 if(k!=root&&ancestor[i]>=D[k])
34 cut[k]=1;
35 }
36 }
37 color[k]=black;
38 A[k]=++tme;//時間戳
39 }
40 int main()
41 {
42 int t1,t3;
43 char t2;
44 while(scanf("%d",&n)&&n)
45 {
46 cnt=0;
47 memset(map,0,sizeof(map));
48 memset(cut,0,sizeof(cut));
49 memset(ancestor,0,sizeof(ancestor));
50 memset(color,0,sizeof(color));
51 memset(D,0,sizeof(D));
52 while(scanf("%d",&t1)&&t1)
53 {
54 while((t2=getchar())!='\n')
55 {
56 scanf("%d",&t3);
57 map[t1][t3]=map[t3][t1]=1;
58 }
59 }
60 dfs(1,0,1);
61 for(int i=1;i<=n;++i)
62 if(cut[i])cnt++;
63 printf("%d\n",cnt);
64 }
65 return 0;
66 }
67