# include <fstream>
 # include <algorithm>

 # define dim 200002

 using namespace std;

 ifstream f("apm.in");
 ofstream g("apm.out");

 struct apm
 {
	 int n1, n2, cost;
 };

 apm a[ dim ];

 int cmp( apm a, apm b )
 {
	 return a.cost < b.cost;
 }

 int n, m;
 int c[ dim ], costmin, amin[ dim ];

 void citire()
 {
	 int i;
 
	 f >> n >> m;
	 
     for ( i = 1 ; i <= m ; i++ )
		 
		 f >> a[ i ].n1 >> a[ i ].n2 >> a[ i ].cost;
 
 }
 
 int cauta( int x )
 {
	 int r, y;
  
     r = x;
  
     while ( c[ r ] != r )
	    r = c[ r ];
  
     while ( c[ x ] != x )
	 {
		 y = c[ x ];
		 c[ x ] = r;
		 x = y;
	 }
	 
	 return r;
 }

 void conex()
 {
	 int i;
	 for ( i = 1 ; i <= n ; i++ )
		 c[ i ] = i;
 }
 
 void leaga( int x, int y )
 {
	 c[ x ] = y;
 }

 void rezolva()
 {
	 int i, cnt = 0, m1, m2;
	 sort( a + 1, a + m + 1, cmp );
	 //for ( i = 1 ; i <= m ; i++ )
	 //	 g << a[ i ].n1 << " " << a[ i ].n2 << " " << a[ i ].cost << "\n";
	 //g << "\n";
	 for ( i = 1 ; i <= m && cnt < n ; i++ )
	 {
		 m1 = cauta( a[ i ].n1 );
		 m2 = cauta( a[ i ].n2 );
		 
		 g << m1 << " " << m2 << " " << i << "\n";
	 
		 if ( m1 != m2 )
		 {
			 costmin = costmin + a[ i ].cost;
			 cnt++;
			 amin[ cnt ] = i;
			 leaga( m1, m2 );
		 }
	 }
 }
 
 void afisare()
 {
	 int i;
	 g << costmin << "\n";
	 g << n - 1 << "\n";
	 for ( i = 1 ; i <= n - 1 ; i++ )
		 g << a[ amin[ i ] ].n1 << " " << a[ amin[ i ] ].n2 << "\n";
}

 int main()
 {
	 citire();
	 conex();
	 rezolva();
	// afisare();
	 return 0;
 }