#include <stdio.h>

#define DIM 1005
#define oo 11005

struct nod {int x;
            nod *urm;} *lst[DIM];
struct muchie {int x,y;} v[10*DIM];
int c[DIM][DIM],f[DIM][DIM];
int q[DIM],viz[DIM],t[DIM],sol[10*DIM];
int n,m,minim,fmax,nrt;

void add (int a,int b)
{
    nod *p=new nod;

    p->x=a;
    p->urm=lst[b];
    lst[b]=p;
}

void read ()
{
	int i,z;

	scanf ("%d%d",&n,&m);
	for (i=1; i<=m; ++i)
	{
		scanf ("%d%d%d",&v[i].x,&v[i].y,&z);
		c[v[i].x][v[i].y]+=z;
		c[v[i].y][v[i].x]+=z;
		add (v[i].x,v[i].y);
		add (v[i].y,v[i].x);
	}
}

int min (int a,int b)
{
	if (a<b)
		return a;
	return b;
}

void init ()
{
    int i;

    for (i=1; i<=n; ++i)
        t[i]=viz[i]=0;
}

int bf ()
{
    nod *p;
    int st,dr;

    init ();
    for (viz[q[st=dr=1]=1]=1; st<=dr; ++st)
        if (q[st]!=n)
            for (p=lst[q[st]]; p; p=p->urm)
                if (c[q[st]][p->x]!=f[q[st]][p->x] && !viz[p->x])
                {
                    viz[p->x]=1;
                    q[++dr]=p->x;
                    t[p->x]=q[st];
                }
    return viz[n];
}

void memset (int f[DIM][DIM],int val)
{
    int i,j;

    for (i=0; i<DIM; ++i)
        for (j=0; j<DIM; ++j)
            f[i][j]=val;
}

int flux ()
{
    nod *p;
    int i,flow;

    memset (f,0);
    for (flow=0; bf (); )
		for (p=lst[n]; p; p=p->urm)
			if (f[p->x][n]!=c[p->x][n] && viz[p->x])
            {
    			t[n]=p->x;
				minim=oo;
    			for (i=n; i!=1; i=t[i])
    				minim=min (minim,c[t[i]][i]-f[t[i]][i]);
    			if (minim!=0)
					for (i=n; i!=1; i=t[i])
        			{
        				f[t[i]][i]+=minim;
        				f[i][t[i]]-=minim;
                    }
    			flow+=minim;
        	}
    return flow;
}

void solve ()
{
    int i,nflow;

    for (i=1; i<=m; ++i)
    {
        ++c[v[i].x][v[i].y];
        ++c[v[i].y][v[i].x];
        nflow=flux ();
        if (nflow>fmax)
            sol[++nrt]=i;
        --c[v[i].x][v[i].y];
        --c[v[i].y][v[i].x];
    }
}

void print ()
{
    int i;

    printf ("%d\n",nrt);
    for (i=1; i<=nrt; ++i)
        printf ("%d\n",sol[i]);
}

int main ()
{
    freopen ("critice.in","r",stdin);
    freopen ("critice.out","w",stdout);

    read ();
    fmax=flux ();
    solve ();
    print ();

    return 0;
}