Codegazizomonoki

#include <iostream>
#include <bits/stdc++.h>

using namespace std;
bool used[200008] , used1[200008];
vector <int> g[200008],r;
map <pair<int, int>, int> z;
int timer = 0, fup[200008], tin[200008];

void dfs (int v, int p  ){
    used[v] = 1;
    int childs = 0;
    tin[v]= fup[v] = timer++;
    for(int i =0; i < g[v].size(); i++){
        int to = g[v][i];
        if(to == p){
            continue;
        }
        if(used[to]){
            fup[v] = min(fup[v], tin[to]);
        }
        else{
            dfs(to, v);
            fup[v] = min(fup[v], fup[to]);
            if(fup[to] >= tin[v] && p != -1 && !used1[v]){
                r.push_back(v);
                used1[v] = 1;
            }
            childs++;
        }
    }
        if (p == -1 && childs > 1 && !used1[v]){
            r.push_back(v);
            used1[v] = 1;
        }
}

int main()
{
    freopen("points.in", "r", stdin);
    freopen("points.out", "w", stdout);
    ios::sync_with_stdio(0);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    for(int i =1; i <=m; i++){
        int L, R;
        cin >> L >> R;
        g[L].push_back(R);
        g[R].push_back(L);
    }
    dfs(1, -1);
    sort(r.begin(), r.end());
    cout << r.size() << endl;
    for(int i =0; i < r.size(); i++){
        cout << r[i] << endl;
    }


}