#include<stdio.h>
#include<algorithm>
#include<vector>
#include<queue>
#define pb push_back
#define maxn 1005
#define maxm 10005
#define inf 0x3f3f3f3f
using namespace std;

int n,m,nr,flow;
int v[maxn],father[maxn],used[2][maxn];
int X[maxm],Y[maxm];
int c[maxn][maxn],f[maxn][maxn];
vector<int> l[maxn],sol;

void read()
{
    int x,y,cst;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x,&y,&cst);
        c[x][y]=c[y][x]=cst;
        l[x].pb(y); l[y].pb(x);
        X[i]=x; Y[i]=y;
    }
}

int bfs()
{
    int k;
    queue<int> q;

    for(q.push(1),v[1]=nr,father[1]=0;!q.empty();q.pop())
    {
        k=q.front();
        if(k==n) continue;
        for(unsigned int i=0;i<l[k].size();i++)
         if(v[l[k][i]]!=nr && c[k][l[k][i]]>f[k][l[k][i]])
         {
             q.push(l[k][i]); v[l[k][i]]=nr;
             father[l[k][i]]=k;
         }
    }
    if(v[n]==nr) return 1;
    return 0;
}

void ed_karp()
{
    int Min; nr=1;
    while(bfs())
    {
        for(unsigned int i=0;i<l[n].size();i++)
         if(v[l[n][i]]==nr && f[l[n][i]][n]!=c[l[n][i]][n])
         {
             Min=inf;
             father[n]=l[n][i];
             for(int j=n;j!=1;j=father[j])
              Min=min(Min,c[father[j]][j]-f[father[j]][j]);

             for(int j=n;j!=1;j=father[j])
             {
                 f[father[j]][j]+=Min;
                 f[j][father[j]]-=Min;
             }
             flow+=Min;
         }
         nr++;
    }
}

void BFS(int source,int ind)
{
    int k;
    queue<int> q;

    used[ind][1]=1;
    for(q.push(source);!q.empty();q.pop())
    {
        k=q.front();
        for(unsigned int i=0;i<l[k].size();i++)
         if(!used[ind][l[k][i]] && c[k][l[k][i]]>f[k][l[k][i]] && c[l[k][i]][k]>f[l[k][i]][k])
         {
             q.push(l[k][i]);
             used[ind][l[k][i]]=1;
         }
    }
}

void solve()
{
    for(int i=1;i<=m;i++)
      if( (used[0][X[i]] && used[1][Y[i]]) || (used[1][X[i]] && used[0][Y[i]]) )
       sol.pb(i);
}

void print()
{
    printf("%d\n",sol.size());
    for(unsigned int i=0;i<sol.size();i++)
     printf("%d\n",sol[i]);
}

int main()
{
    freopen("critice.in","r",stdin);
    freopen("critice.out","w",stdout);

    read();
    ed_karp();
    BFS(1,0);
    BFS(n,1);
    solve();
    print();

    fclose(stdin);
    fclose(stdout);
    return 0;
}