public static void main(String[] args)

{

Scanner sc = new Scanner(System.in);

int node = sc.nextInt(); //no.of nodes

ArrayList<ArrayList<Integer>> ans = new ArrayList<>();

//for 1 base indexing i.e starting vertex from 1 to V

for(int i = 0; i <= node; i )

{

ans.add(new ArrayList<>());

}

int edges = sc.nextInt(); //no. of edges

//making graphs by joining vertices with edges

for(int i = 1; i <= edges; i )

{

System.out.println("Enter u and v");

int u = sc.nextInt();

int v = sc.nextInt();

ans.get(u).add(v);

ans.get(v).add(u);

}

//bfs

ArrayList<Integer> print = new ArrayList<>();

//V 1 for 1 based indexing nodes---> nodes start from 1 to V not 0 to V-1

boolean[] bool = new boolean[node 1];

//using loop inorder to check every node is traversed using bfs or not

//helpful for unconnected graph

for(int i = 1; i <= node; i )

{

//check if current node is visited or not

if(!bool[i])

{

Queue<Integer> q = new LinkedList<>();

q.add(i);

bool[i] = true;

while(!q.isEmpty())

{

//take out node from queue and mark it as visited

int nd = q.poll();

print.add(nd);

//traverse neighbour nodes of curr nodes

for(Integer neighbour : ans.get(node))

{

if(!bool[neighbour])

{

q.add(neighbour);

bool[neighbour] = true;

}

}

}

}

}

System.out.println(print);

}