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#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int N = 1e4+10, M = 1e5+10;
struct {
int v, next;
} e[M<<1];
int low[M], que[M], cnt, head[M], stack[M], top, indexx, dfn[M];
bool cut[M];
bool instack[M];
void add(int u,int v)
{
e[++cnt].next = head[u];
e[cnt].v = v;
head[u] = cnt;
}
void tarjan(int x,int pre)
{
int child = 0;
low[x] = dfn[x] = ++indexx;
stack[++top]=x;
instack[x]=1;
for (int i = head[x]; i;i=e[i].next)
{
int v = e[i].v;
if(!dfn[v])
{
tarjan(v, x);
low[x] = min(low[x], low[v]);
if(x!=pre&&dfn[x]<=low[v])
cut[x] = 1;
if(x==pre)
child++;
}
else if(instack[v])
low[x] = min(low[x], dfn[v]);
}
if(child>1&&x==pre)
cut[x] = 1;
}
void init()
{
memset(head, 0, sizeof head);
}
int main()
{
init();
int n, m;
cin >> n >> m;
for (int i = 1; i <= m;i++)
{
int a, b;
cin >> a >> b;
add(a, b), add(b, a);
}
for(int i = 1;i <= n;i++) {
if(!dfn[i]) tarjan(i,i);
}
int ans = 0;
for(int i = 1;i <= n;i++) ans += cut[i];
printf("%dn",ans);
for(int i = 1;i <= n;i++) {
if(cut[i]) printf("%d ",i);
}
return 0;
}
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