#include<fstream>
using namespace std;
ifstream fin("k.in");
ofstream fout("k.out");
const int inf=1<<20;
int n,m,A[100][100],P[100];

void citire()
{    int i,j,k,c;
     fin>>n>>m;
     for(i=1;i<n;i++)
        for(j=i+1;j<=n;j++)
            A[i][j]=A[j][i]=inf;
     for(int k=1;k<=m;k++)
        { fin>>i>>j>>c;
          A[i][j]=A[j][i]=c;
        }
}

int main()
{
    int i,j,k,minn,x,y;
    citire();
    P[1]=1;
    for(k=1;k<n;k++)
    {
       minn=inf;
       for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
           if(P[i] && !P[j] && A[i][j]<minn)
           {
               minn=A[i][j]; x=i;y=j;
           }
       fout<<x<<" "<<y<<" "<<A[x][y]<<endl;
       P[y]=1;
    }
    fin.close();
    fout.close();
    return 0;
}

//varianta eficienta

#include<fstream>
using namespace std;
ifstream fin("k.in");
ofstream fout("k.out");
const int inf=1<<20;
int n,m,A[100][100],P[100];

void citire()
{    int i,j,k,c;
     fin>>n>>m;
     for(i=1;i<n;i++)
        for(j=i+1;j<=n;j++)
            A[i][j]=A[j][i]=inf;
     for(int k=1;k<=m;k++)
        { fin>>i>>j>>c;
          A[i][j]=A[j][i]=c;
        }
}

int main()
{
    int i,k,minn,x;
    citire();
    for(i=2;i<=n;i++) P[i]=1;
    for(k=1;k<n;k++)
    {
       minn=inf;
       for(i=1;i<=n;i++)
           if(P[i] && A[P[i]][i]<minn)
           {
               minn=A[P[i]][i]; x=i;
           }
       fout<<P[x]<<" "<<x<<" "<<A[P[x]][x]<<endl;
       for(i=1;i<=n;i++)
           if(P[i] && A[P[i]][i]>A[i][x])
                P[i]=x;
       P[x]=0;
    }
    fin.close();
    fout.close();
    return 0;
}