#include<stdio.h>
#include<vector>
using namespace std;

#define NMAX 1005
#define minim(a,b) (a<b ? a : b)
#define INF 1000000006
#define pi pair<int,int>
#define f first
#define s second
#define mp make_pair
#define pb push_back

int n,m,nr,sol[10*NMAX];
short int flux[NMAX][NMAX];
short int cap[NMAX][NMAX];
int q[NMAX];
int pred[NMAX];
pi mc[10*NMAX];
vector<int> v[NMAX];
char viz[NMAX];

int bfs()
{
    int i,inc,sf,x,lim,nod;
    
    memset(viz,0,sizeof(viz));
    memset(pred,-1,sizeof(pred));
    viz[1]=1;
    inc=sf=1;
    q[1]=1;
    while(inc<=sf)
    {
        nod=q[inc];
        lim=v[nod].size();
        for(i=0;i<lim;i++)
            if(!viz[x=v[nod][i]] && flux[nod][x]<cap[nod][x])
            {
                viz[x]=1;
                pred[x]=nod;
                q[++sf]=x;
                if(x==n)
                    return 1;
            }
        inc++;
    }
    return 0;
}

int main ()
{
    int i,a,b,c,poz,val;
    
    freopen("critice.in","r",stdin);
    freopen("critice.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d%d",&a,&b,&c);
        cap[a][b]+=c;
        cap[b][a]+=c;
        v[a].pb(b);
        v[b].pb(a);
        mc[i]=mp(a,b);
    }
    while(bfs())
    {
        val=INF;
        for(poz=n;pred[poz]!=-1;poz=pred[poz])
            val=minim(val,cap[pred[poz]][poz]-flux[pred[poz]][poz]);
        for(poz=n;pred[poz]!=-1;poz=pred[poz])
        {
            flux[pred[poz]][poz]+=val;
            flux[poz][pred[poz]]-=val;
        }
    }
    for(i=1;i<=m;i++)
    {
        cap[mc[i].f][mc[i].s]++;
        cap[mc[i].s][mc[i].f]++;
        if(bfs())
            sol[++nr]=i;
        cap[mc[i].f][mc[i].s]--;
        cap[mc[i].s][mc[i].f]--;
    }
    printf("%d\n",nr);
    for(i=1;i<=nr;i++)
        printf("%d\n",sol[i]);
    return 0;
}