#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <stdlib.h>
#define nmax 1005
using namespace std;
ifstream f("critice.in");
ofstream g("critice.out");
int n,m, cp[nmax][nmax], fx[nmax][nmax], viz[nmax], t[nmax], viz1[nmax];
vector <int> v[nmax],sol;
queue  <int> q;
struct bla{
int x,y;
}M[10*nmax];

void citire()
{
    int i,j,k,c;
    f>>n>>m;
    for(k=1; k<=m; k++)
    {
        f>>i>>j>>c;
        v[i].push_back(j);
        v[j].push_back(i);
        cp[i][j]= cp[j][i]= c;
        M[k]={i,j};
    }
}

int bfs()
{
    int nod,i;
    while(!q.empty()) q.pop();
    for(i=1; i<=n; i++) viz[i]=0;

    viz[1]=1;
    q.push(1);
    while(!q.empty())
    {
        nod=q.front();
        q.pop();
        for(i=0; i<v[nod].size(); i++)
            if(!viz[v[nod][i]] && cp[nod][v[nod][i]]>fx[nod][v[nod][i]])
        {
            q.push(v[nod][i]);
            viz[v[nod][i]]=1;
            t[v[nod][i]]=nod;
            if(v[nod][i]==n)
                return 1;
        }
    }
    return 0;
}

int flux_minim()
{
    int nod, flux, fmin,j;
    for(flux=0; bfs();)
     for(j=0; j<v[n].size(); j++)
      if(viz[v[n][j]] && abs(cp[v[n][j]][n]) > abs(fx[v[n][j]][n]) )
    {
        t[n]=v[n][j];
        fmin=1e9;
        for(nod=n; nod!=1; nod=t[nod])
            fmin=min(fmin, cp[t[nod]][nod]-fx[t[nod]][nod]);
        for(nod=n; nod!=1; nod=t[nod])
        {
            fx[nod][t[nod]]-= fmin;
            fx[t[nod]][nod]+= fmin;
        }
    flux+=fmin;
    }
    return flux;
}

void dfs(int nod, int mark)
{
    int i;
    viz1[nod]=mark;
    for(i=0; i<v[nod].size(); i++)
    if(!viz1[v[nod][i]] && abs(cp[nod][v[nod][i]]) > abs(fx[nod][v[nod][i]]) )
        dfs(v[nod][i], mark);
}

int main()
{
    citire();
    int fl,i, nr=0;
    fl=flux_minim();

    for(i=1; i<=n; i++)
        viz1[i]=0;
    dfs(1,1);
    dfs(n,2);

    for(i=1; i<=m; i++)
        if(viz1[M[i].x] && viz1[M[i].y] && viz1[M[i].x]!=viz1[M[i].y])
            {nr++; sol.push_back(i);}
    g<<nr<<"\n";
    for(i=0; i<sol.size(); i++)
        g<<sol[i]<<"\n";
    f.close();
    g.close();
    return 0;
}