#include 
#include 
#include 
#include 
using namespace std;
const int maxk=1e5+10;
int n, m;
vectorgraph[maxk];
vectorart;
int low_link[maxk];
int dist[maxk];
bool visited[maxk];
int current_time=0;
void dfs(int node, int parent=-1){
    visited[node]=true;
    low_link[node]=current_time;
    dist[node]=current_time;
    current_time++;
    int children = 0;
    for(int i=0; i<(int)graph[node].size(); i++){
        int sosed=graph[node][i];
        if(sosed!=parent){
            if(visited[sosed]==true){
                low_link[node]=min(low_link[node], dist[sosed]);
            }
            else{
                dfs(sosed, node);
                low_link[node]=min(low_link[node], low_link[sosed]);
                if(parent!=-1 and low_link[sosed]>=dist[node]){
                    art.push_back(node);
                }
                children++;
            }
        }
    }
    if(parent == -1 and children > 1) {
        art.push_back(node);
    }
}
void articulation_points(){
    for(int i=0; i>n>>m;
        if(n == 0 and m == 0) {
            break;
        }
        for(int i=0; i>a>>b;
            a--;
            b--;
            graph[a].push_back(b);
            graph[b].push_back(a);
        }
        current_time=0;
        articulation_points();
        cout<