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

#define Nmax 1001
#define Mmax 10001

int N,M,i,f[Nmax][Nmax],parinte[Nmax],x[Mmax],y[Mmax],aux[Nmax],c,nr;
vector<int> g[Nmax];

void citire()
{
 int i;
 freopen("critice.in","r",stdin);
 scanf("%d %d",&N,&M);
 for (i=1;i<=M;++i)
     {
     scanf("%d %d %d",&x[i],&y[i],&c);
     g[x[i]].push_back(y[i]);
     g[y[i]].push_back(x[i]);
     f[x[i]][y[i]]=f[y[i]][x[i]]=c;
     }
}

int bfs()
{
int coada[Nmax],st,dr,aux;
vector<int>::iterator i;
memset(parinte,0,sizeof(parinte));
parinte[coada[st=dr=1]=1]=1;
while ((st<=dr)&&(parinte[N]==0))
      {
      aux=coada[st];
      for (i=g[aux].begin();(i<g[aux].end()) && (parinte[N]==0);++i)
          if ((f[aux][*i])&&(parinte[*i]==0))
                parinte[coada[++dr]=*i]=aux;
             else if (f[aux][*i]==0) g[aux].erase(i--);
      ++st;
      }
return parinte[N];
}

void flux()
{
int cmin,p;
while ( bfs() )
      {
      cmin=f[N][p=parinte[N]];
      while (p!=1)
            {
            cmin=(f[parinte[p]][p]<cmin?f[parinte[p]][p]:cmin);
            p=parinte[p];
            }
      p=N;
      while (p!=1)
            {
            f[p][parinte[p]]=(f[parinte[p]][p]-=cmin);
            p=parinte[p];
            }
      }
}

void bfs_source()
{
int coada[Nmax],st,dr;
vector<int>::iterator i;
coada[st=dr=1]=1;
memset(parinte,0,sizeof(parinte));
parinte[1]=1;
while (st<=dr)
      {
      for (i=g[coada[st]].begin();i<g[coada[st]].end();++i)
          if ((f[coada[st]][*i]!=0)&&(parinte[*i]==0))
             {
             parinte[coada[++dr]=*i]=1;
             }
      ++st;
      }
}

void bfs_destination()
{
int coada[Nmax],st,dr;
vector<int>::iterator i;
coada[st=dr=1]=N;
aux[N]=1;
while (st<=dr)
      {
      for (i=g[coada[st]].begin();i<g[coada[st]].end();++i)
          if ((f[coada[st]][*i]!=0)&&(aux[*i]==0))
             {
             aux[coada[++dr]=*i]=1;
             }
      ++st;
      }
}

int main()
{
 citire();
 flux();
 bfs_source();
 bfs_destination();
 freopen("critice.out","w",stdout);
 printf("       \n");
 for (i=1;i<=M;++i)
     if ((f[x[i]][y[i]]==0)&&((parinte[x[i]]+aux[y[i]]==2)||(parinte[y[i]]+aux[x[i]]==2)))
        {
        printf("%d\n",i);
        ++nr;
        }
 fseek(stdout,0,SEEK_SET);
 printf("%d",nr);
 fclose(stdout);
 return 0;
}