//Link->https://practice.geeksforgeeks.org/problems/depth-first-traversal-for-a-graph/1

// { Driver Code Starts

#include<bits/stdc++.h>

using namespace std;

// } Driver Code Ends

/* Function to do DFS of graph

g : adjacency list of graph

N : number of vertices

return a list containing the DFS traversal of the given graph

*/

void dfsTraverseRecur(bool visited[],vector<int> adj[],int v,vector<int> &vect) {

visited[v]=true;

vect.push_back(v);

for(vector<int>::const_iterator it=adj[v].begin(); it!=adj[v].end(); it++) {

if(visited[*it]!=true) {

dfsTraverseRecur(visited,adj,*it,vect);

}

}

}

vector <int> dfs(vector<int> g[], int N)

{

// Your code here

bool visited[N];

vector<int> vect;

for(int i=0; i<N; i++)

visited[i]=false;

dfsTraverseRecur(visited,g,0,vect);

return vect;

}

// { Driver Code Starts.

int main()

{

int T;

cin>>T;

while(T--)

{

int N, E;

cin>>N>>E;

vector<int> g[N];

bool vis[N];

memset(vis, false, sizeof(vis));

for(int i=0;i<E;i++)

{

int u,v;

cin>>u>>v;

g[u].push_back(v);

g[v].push_back(u);

}

vector <int> res = dfs(g, N);

for (int i = 0; i < res.size (); i++)

cout << res[i] << " ";

cout<<endl;

}

} // } Driver Code Ends