1 /*COGS 08
 2    by S.B.S.*/
 3 #include<iostream>
 4 #include<cstdio>
 5 #include<cstring>
 6 #include<cmath>
 7 #include<algorithm>
 8 #include<queue>
 9 #include<cstdlib>
10 #include<iomanip>
11 #include<cassert>
12 #include<climits>
13 #define maxn 121
14 #define inf 0x7fffffff
15 #define F(i,j,k) for(int i=j;i<=k;i++)
16 #define FF(i,j,k) for(int i=j;i>=k;i--)
17 #define M(a,b) memset(a,b,sizeof(b))
18 using namespace std;
19 int read(){
20     int x=0,f=1;char ch=getchar();
21     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
22     while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
23     return x*f;
24 }
25 vector<int> edge[maxn];
26 int n,m,dfn[maxn],low[maxn];
27 int cnt,tim=0,cut;
28 int root;
29 int ans=0;
30 inline void addedge(int u,int v)
31 {
32      edge[u].push_back(v);
33      edge[v].push_back(u);
34 }
35 bool gd[maxn];
36 inline void dfs(int u)
37 {
38     low[u]=dfn[u]=++tim;
39     int v;int tot=0;
40     F(i,0,edge[u].size()-1)
41         { 
42             v=edge[u][i];
43              if(!dfn[v]){
44                  dfs(v);
45                  tot++;
46                  low[u]=min(low[v],low[u]);
47                  if((u==root&&tot>1)||(u!=root&&low[v]>=dfn[u]))
48                 if(!gd[u])
49                 {
50                         gd[u]=true;
51                         ans++;
52                  } 
53         }
54         else 
55             low[u]=min(low[u],dfn[v]);
56      }
57 }
58 int main()
59 {
60     std::ios::sync_with_stdio(false);
61     freopen("gd.in","r",stdin);
62     freopen("gd.out","w",stdout);
63     int n,m;
64     cin>>n;int x,y;
65     while(cin>>x>>y)
66     {
67         addedge(x,y);
68     }
69     F(i,1,n)
70     {
71         if(!dfn[i])
72         {
73             root=i;
74             dfs(i);
75         }
76     }
77     cout<<ans<<endl;
78     F(i,1,n){
79         if(gd[i]) cout<<i<<endl;
80     }
81     return 0;
82 }