#include<fstream>
#include<queue>
#include<cstring>
using namespace std;
inline int Min(int a,int b)
{
    if (a<b) return a;
        else return b;
}
struct muchie
{
    int x,y;
}muc[10005];
vector<int>v[1005];
int f[1005][1005],c[1005][1005],tata[1005];
int n,m,x,y,z,viz[1005],viz1[1005],sol[10005],k,i;
int q[1005],st,dr;
int BFS()
{
    int i;
   q[1]=1;st=1;dr=1;
    memset(viz,0,sizeof(viz));
    viz[1]=1;
    while(st<=dr)
    {
        int nod=q[st];
        st++;
        for (i=0;i<v[nod].size();++i)
        {
            int varf=v[nod][i];
            if (c[nod][varf]>f[nod][varf] && viz[varf]==0)
            {
                if (varf==n) return 1;
                q[++dr]=varf;
                tata[varf]=nod;
                viz[varf]=1;
            }
        }
    }
    return viz[n];
}
int BFS1()
{
    int i;
    q[1]=n;st=1,dr=1;
    viz1[n]=1;
    while(st<=dr)
    {
        int nod=q[st];
        ++st;
        for (i=0;i<v[nod].size();++i)
        {
            int varf=v[nod][i];
            if (c[nod][varf]>f[nod][varf]*(-1) && viz1[varf]==0)
            {
                if (varf==1) return 1;
                q[++dr]=varf;
                tata[varf]=nod;
                viz1[varf]=1;
            }
        }
    }
    return 0;
}
int main()
{
    ifstream cin("critice.in");
    ofstream cout("critice.out");
    cin>>n>>m;
    for (i=1;i<=m;++i)
    {
        cin>>x>>y>>z;
        muc[i].x=x;
        muc[i].y=y;
        v[x].push_back(y);
        v[y].push_back(x);
        c[x][y]=z;
        c[y][x]=z;
    }
    int flux=0;
    while(BFS())
    {
        for (i=0;i<v[n].size();++i)
        {
            int nod=v[n][i];
            if (f[nod][n]==c[nod][n] || !viz[nod]) continue;
            tata[n]=nod;
            int fmin=c[tata[nod]][nod]-f[tata[nod]][nod];
            for (nod=n;nod!=1;nod=tata[nod])
                fmin=Min(fmin,c[tata[nod]][nod]-f[tata[nod]][nod]);
            if (fmin==0) continue;
            for (nod=n;nod!=1;nod=tata[nod])
                {
                    f[tata[nod]][nod]+=fmin;
                    f[nod][tata[nod]]-=fmin;
                }
            flux+=fmin;
        }
    }
    x=BFS();
    x=BFS1();
    for (i=1;i<=m;++i)
        if ((viz[muc[i].x] && viz1[muc[i].y]) || (viz[muc[i].y] && viz1[muc[i].x]))
            sol[++k]=i;
    cout<<k<<"\n";
    for (i=1;i<=k;++i) cout<<sol[i]<<"\n";
    return 0;
}