#include<cstring>
#include<fstream>
#include<iostream>
#include<queue>
#include<vector>
#include<stdlib.h>
#define NMAX (1<<10)
#define oo (1<<30)
using namespace std;
ifstream in("critice.in");
ofstream out("critice.out");
int n,m,x,y,z,minim,no;
int p[NMAX][NMAX],fl[NMAX][NMAX],daddy[NMAX];
bool viz[NMAX];
vector<int>graph[NMAX];
queue<int>chiu;
pair<int,int>edge[10*NMAX];
void scan()
{
    in>>n>>m;
    for(int i=0;i<m;i++)
    {
        in>>x>>y>>z;
        graph[x].push_back(y);
        graph[y].push_back(x);
        p[x][y]=p[y][x]=z;
        edge[i]=make_pair(x,y);
    }
}
bool bf()
{
    memset(viz, 0, sizeof(viz));
    while(!chiu.empty())
        chiu.pop();
    chiu.push(1);
    viz[1]=1;
    while(!chiu.empty())
    {
        int node=chiu.front();
        chiu.pop();
        for(size_t i=0;i<graph[node].size();i++)
        {
            int neigh=graph[node][i];
            if(!viz[neigh]&p[node][neigh]>fl[node][neigh])
            {
                chiu.push(neigh);
                daddy[neigh]=node;
                viz[neigh]=1;
                if(neigh==n)
                    return true;
            }
        }
    }
    return false;
}
void EK()
{
    scan();
    while(bf())
    {
        for(int i=0;i<graph[n].size();i++)
        {
            int vertex=graph[n][i];
            if(viz[vertex]&(p[vertex][n]!=fl[vertex][n]))
            {
                daddy[n]=vertex;
                minim=oo;
            for(no=n;no!=1;no=daddy[no])
                minim= min(minim,p[daddy[no]][no]-fl[daddy[no]][no]);
            if(minim!=0)
                {
                for(no=n;no!=1;no=daddy[no])
                    {
                        fl[daddy[no]][no]+=minim;
                        fl[no][daddy[no]]-=minim;
                    }
                }
            }
        }
    }
}
int visited[NMAX];
void df(int start, int value)
{
    visited[start]=value;//value ia valoarea 1 pentru sensul 1->n, iar 2 pentru sensul n->1
    for(int i=0;i<graph[start].size();i++)
    {
        int next=graph[start][i];
        if(!visited[next])
            if(abs(p[start][next])>abs(fl[start][next]))
                df(next,value);
    }
}
vector<int>sol;
int main()
{
    EK();
    df(1,1);
    df(n,2);
    int i,nosol=0;
    for(i=0;i<m;i++)
    {
        if(visited[edge[i].first]&&visited[edge[i].second]&&visited[edge[i].first]!=visited[edge[i].second])
            {
                sol.push_back(i+1);
                nosol++;
            }
    }
    out<<nosol<<endl;
    for(i=0;i<nosol;i++)
        out<<sol[i]<<endl;

}