freopen("input.txt", "r", stdin);

freopen("op.txt", "w", stdout);

ios::sync_with_stdio(0);

cin.tie(0);

int t;

cin>>t;

while(t--)

{

int v,e;

cin>>v>>e;

vector<int> gp[v];

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

{

int a,b;

cin>>a>>b;

gp[a].push_back(b);

gp[b].push_back(a);

}

for(int j=0; j<v; j++)

{

cout<<j<<"";

for(auto z: gp[j])

cout<<"-> "<<z<<"";

cout<<"\n";

}

}

return 0;

queue<int> q;

vector<int> ans;

q.push(0);

bool vis[N+1] = {false};

while(!q.empty())

{

int n = q.front();

q.pop();

ans.push_back(n);

for(auto si: g[n])

if(!vis[si])

{

vis[si] = true;

q.push(si);

}

}

return ans;

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

bool vis[N+1] = {false};

vector<int> ans;

stack<int> s;

s.push(0);

ans.push(0);

vis[0] = true;

int i=0;

while(!s.empty())

{

int i = s.pop();

for(auto ch : g[i])

{

if(!vis[ch])

}

}

}

// dfs

bool vis[N+1] = {false};

vector<int> adj;

vecotr<int> ans;

vector<int> dfs(vector<int> adj[], int i, vector< int> ans )

{

vis[i] = true;

ans.push_back(i);

for(auto it : adj[i])

{

if(!vis[it])

dfs(adj,it,ans);

}

return ans;

}

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

{

if(!vis[i])

dfs(adj, i, ans);

}