#include <fstream>
#include <cstdio>
#include <vector>
#include <queue>
#define VAL 1005
#define MC 10005
#define INF 1000000000

using namespace std;

int N, M, i, j, C;
int flux[VAL][VAL];
int prec[VAL], X, A, B;
bool viz[VAL];
pair <int, int> Mc[MC];
vector <int> G[VAL], SOL;
vector <int> :: iterator it;
queue <int> Q;

bool BFS(int second, int D)
{
    for (j=1; j<=N; j++)
      viz[j]=false;
    viz[second]=true;
    Q.push(second);
    while (Q.empty()==false)
    {
        second=Q.front();
        Q.pop();
        if (second==D)
          continue;
        for (it=G[second].begin(); it!=G[second].end(); it++)
        {
            if (viz[*it]==false && flux[second][*it]>0)
            {
                viz[*it]=true;
                prec[*it]=second;
                Q.push(*it);
            }
        }
    }
    return viz[D]==true;
}

void Ford_Fulkerson()
{
    while (BFS(1, N)==true)
    {
        for (i=0; i<G[N].size(); i++)
        {
            X=INF;
            prec[N]=G[N][i];
            for (j=N; j!=1; j=prec[j])
              X=min(X, flux[prec[j]][j]);
            if (X==0)
              continue;
            for (j=N; j!=1; j=prec[j])
            {
                flux[prec[j]][j]-=X;
                flux[j][prec[j]]+=X;
            }
        }
    }
}

bool Check(pair <int, int> M)
{
    return ((BFS(1, M.first)==1 && BFS(M.second, N)==1) || (BFS(1, M.second)==1 && BFS(M.first, N)==1));
}

int main()
{
    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);
        Mc[i].first=A;
        Mc[i].second=B;
        flux[Mc[i].first][Mc[i].second]=C;
        flux[Mc[i].second][Mc[i].first]=C;
        G[Mc[i].first].push_back(Mc[i].second);
        G[Mc[i].second].push_back(Mc[i].first);
    }
    Ford_Fulkerson();
    for (i=1; i<=M; i++)
      if ((flux[Mc[i].first][Mc[i].second]==0 || flux[Mc[i].second][Mc[i].first]==0) && Check(Mc[i])==true)
        SOL.push_back(i);
    printf("%d\n", SOL.size());
    for (i=0; i<SOL.size(); i++)
      printf("%d\n", SOL[i]);
    return 0;
}