# include <fstream>
# include <iostream>
using namespace std;
struct bla{
	int c, ind;};

bla c[1024][1024];
int n, m, t[1024], crt[1024], nrc;

void read ()
{
	ifstream fin ("critice.in");
	fin>>n>>m;
	for (int i=1;i<=m;i++)
	{
		int a, b, co;
		fin>>a>>b>>co;
		c[a][b].c=co;
		c[a][b].ind=i;
		c[b][a].c=co;
		c[b][a].ind=i;
	}
}

int verif (int s, int d)
{
	int co[1024], st, dr, k, tt[1024];
	for (int i=1;i<=n;i++)
		tt[i]=-1;
	st=dr=1;
	co[st]=s;
	tt[s]=0;
	while (st<=dr)
	{
		k=co[st++];
		for (int i=1;i<=n;i++)
			if (tt[i]==-1 && c[k][i].c>0)
			{
				tt[i]=k;
				if (i==d)
					return 1;
				co[++dr]=i;
			}
	}
	return 0;
}

int bfs (int s, int d)
{
	int co[2048], st, dr, k;
	for(int i=1;i<=n;i++)
		t[i]=-1;
	st=dr=1;
	co[st]=s;
	t[s]=0;
	while (st<=dr)
	{
		k=co[st++];
		for (int i=2;i<=n;i++)
			if (c[k][i].c>0 && t[i]==-1)
			{
				t[i]=k;
				if (i==d)
					return 1;
				co[++dr]=i;
			}
			else
				if (c[k][i].ind && c[k][i].c==0 && verif(i, n))
					{
						crt[++nrc]=c[k][i].ind;				
						c[k][i].c=-1;
					}
	}
	return 0;
}

void EK ()
{
	int cmin;
	while (bfs(1, n))
	{
		cmin=1000000000;
		for(int i=n;t[i];i=t[i])
			if (c[t[i]][i].c<cmin)
				cmin=c[t[i]][i].c;
		for (int i=n;t[i];i=t[i])
		{
			c[t[i]][i].c-=cmin;
			c[i][t[i]].c-=cmin;
		}
	}
}

void write ()
{
	ofstream fout ("critice.out");
	fout<<nrc<<endl;
	for (int i=1;i<=nrc;i++)
		fout<<crt[i]<<endl;
}		

int main ()
{
	read ();
	EK ();
	write ();
	return 0;
}