#include<iostream>

#include<list>

#define NIL -1

using namespace std;

class Graph{

int v;

list<int> *adj; // Dynamic array of adjacency lists

bool isBCUtil(int v,bool vis[],int disc[],int low[],int par[]);

public:

Graph(int v);

void AddEdge(int v,int w);

bool isBC();

};

Graph::Graph(int v){

this->v=v;

adj=new list<int>[v];

}

void Graph::AddEdge(int v,int w){

adj[v].push_back(w);

adj[w].push_back(v);

}

bool Graph::isBCUtil(int u,bool vis[],int disc[],int low[],int par[]){

static int time=0;

// Count of children in dfs tree

int child=0;

// Mark current node visited

vis[u]=true;

// Initialise discovery time and low value

disc[u]=low[u]=++time;

for(auto x:adj[u]){

// if x is not visited yet then make it a child of u in dfs tree and recur for it

if(!vis[x]){

child++;

par[x]=u;

if(isBCUtil(x,vis,disc,low,par)) return true;

low[u]=min(low[u],low[x]);

// check if subtree rooted with x has a connection to one of ancestors of u

if(par[u]!=-1 and low[x]>=disc[u]) return true;

// if u is root of dfs tree and has two or more children

if(par[u]==-1 and child>1) return true;

}

else if(x!=par[u])

low[u]=min(low[u],disc[x]);

}

return false;

}

bool Graph::isBC(){

bool *vis=new bool[v];

int *disc=new int[v];

int *low=new int[v];

int *par=new int[v];

for(int i=0;i<v;i++) {

par[i]=-1;

vis[i]=false;

}

if(isBCUtil(0,vis,disc,low,par)) return false;

for(int i=0;i<v;i++){

if(vis[i]==false) return false;

}

return true;

}

int main(){

// create graph over here and call respective functions

}