#include<bits/stdc++.h>

using namespace std;

int getminVertex(vector<int> &weight,vector<bool> &visited,int n)

{

int mini = -1;

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

{

if(!visited[i] && (mini == -1 || weight[i]<weight[mini]))

{

mini =i;

}

}

return mini;

}

void prims(vector<vector<int>> a,int n,int e)

{

vector<int> weight(n,INT_MAX);

vector<int> parent(n);

vector<bool> visited(n,false);

parent[0]=-1;

weight[0]=1;

for(int i=0;i<n-1;i++)

{

int minvertex =getminVertex(weight,visited,n);

visited[minvertex] =true;

// explore all the neighbours of the minimum vertex and update

// parent and weight array after that

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

{

if(!visited[j] && a[minvertex][j]!=0 )

{

if(weight[j] > a[minvertex][j])

{

weight[j] = a[minvertex][j];

parent[j] =minvertex;

}

}

}

}

for(int i=1;i<n;i++)

{

if(parent[i]<i)

{

cout<<parent[i]<<" "<<i<<" "<<weight[i]<<endl;

}

else

{

cout<<i<<" "<<parent[i]<<" "<<weight[i]<<endl;

}

}

}

int main()

{

int n,e;

cin>>n>>e;

vector<vector<int>> mat(n,vector<int> (n));

int x,y,weight;

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

{

cin>>x>>y>>weight;

mat[x][y]=weight;

mat[y][x]=weight;

}

prims(mat,n,e);

return 0;

}