1 #include<iostream>
 2 using namespace std;
 3 #include<cstdio>
 4 #include<cstring>
 5 #define N 102
 6 int low[N],dfn[N],root,topt=0,n,a,b,ans[N];
 7 bool is_gd[N];
 8 struct Edge{
 9     int v,last;
10 }edge[N*N*2];
11 int head[N],t=0;
12 void add_edge(int u,int v)
13 {
14     ++t;
15     edge[t].v=v;
16     edge[t].last=head[u];
17     head[u]=t;
18 }
19 void input()
20 {
21     scanf("%d",&n);
22     while(scanf("%d%d",&a,&b)==2)
23     {
24         add_edge(a,b);
25         add_edge(b,a);
26     }
27 }
28 void tarjan(int k)
29 {/*记住这个模板就好了*/
30     int cnt=0;
31     dfn[k]=low[k]=++topt;
32     for(int l=head[k];l;l=edge[l].last)
33     {
34         int v=edge[l].v;
35         if(!dfn[v])
36         {
37             tarjan(v);
38             ++cnt;
39             low[k]=min(low[k],low[v]);
40             if((root==k&&cnt>1)||(root!=k&&low[v]>=dfn[k]))
41               is_gd[k]=true;
42         }
43         else low[k]=min(low[k],dfn[v]);
44     }
45 }
46 int main()
47 {
48     freopen("gd.in","r",stdin);
49     freopen("gd.out","w",stdout);
50     input();
51     root=1;
52     tarjan(1);
53     for(int i=1;i<=n;++i)
54       if(is_gd[i])
55       ans[++ans[0]]=i;
56     printf("%d\n",ans[0]);
57     for(int i=1;i<=ans[0];++i)
58       printf("%d\n",ans[i]);
59     fclose(stdin);fclose(stdout);
60     return 0;
61 }