#include<cstdio>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;
const int N=1005;
int tot,n,minf,cur,tata[N],nr[N][N],cap[N][N],flux[N][N];
bool viz[N],fd[N],fs[N];
vector<int> rez,L[N];
queue<int> Q;
void read()
{
    int m,x,y,c;
    freopen("critice.in","r",stdin);
    freopen("critice.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x,&y,&c);
        nr[x][y]=i;
        nr[y][x]=i;
        cap[x][y]+=c, L[x].push_back(y);
        cap[y][x]+=c, L[y].push_back(x);
    }
}
bool drum()
{
    Q.push(1);
    for(int i=1;i<=n;i++)
        viz[i]=false;
    viz[1]=true;
    while(!Q.empty())
    {
        int nod=Q.front();
        Q.pop();
        if(nod==n)
            continue;
        for(vector<int>::iterator it=L[nod].begin();it!=L[nod].end();it++)
            if(!viz[*it]  && cap[nod][*it]-flux[nod][*it]>0)
            {
                Q.push(*it);
                viz[*it]=true;
                tata[*it]=nod;
            }
    }
    return viz[n];
}
void compute_min(int nod)
{
    for(int i=nod;i!=1;i=tata[i])
        if(minf>cap[tata[i]][i]-flux[tata[i]][i])
            minf=cap[tata[i]][i]-flux[tata[i]][i];
}
void upgrade_flux(int nod)
{
    for(int i=nod;i!=1;i=tata[i])
    {
        flux[tata[i]][i]+=minf;
        flux[i][tata[i]]+=minf;
    }
}
void dfd(int nod)
{
    for(vector<int>::iterator it=L[nod].begin();it!=L[nod].end();it++)
        if(!fd[*it] && cap[*it][nod]-flux[*it][nod]>0)
        {
            fd[*it]=true;
            dfd(*it);
        }
}
void dfs(int nod)
{
    for(vector<int>::iterator it=L[nod].begin();it!=L[nod].end();it++)
        if(!fs[*it] && cap[nod][*it]-flux[nod][*it]>0)
        {
            fs[*it]=true;
            dfs(*it);
        }
}
void solve()
{
    while(drum())
    {
        for(vector<int>::iterator it=L[n].begin();it!=L[n].end();it++)
            if(viz[*it])
            {
                minf=cap[*it][n]-flux[*it][n];
                compute_min(*it);
                upgrade_flux(*it);
                tot+=minf;
                flux[*it][n]+=minf;
                flux[n][*it]+=minf;
            }
    }
    fs[1]=true;
    dfs(1);
    fd[n]=true;
    dfd(n);
}
void init()
{
    for(int i=1;i<=n;i++)
        for(vector<int>::iterator it=L[i].begin();it!=L[i].end();it++)
            if(cap[i][*it]-flux[i][*it]==0 && fs[i] && fd[*it])
                rez.push_back(nr[i][*it]);
    sort(rez.begin(),rez.end());
    rez.resize(unique(rez.begin(),rez.end())-rez.begin());
}
void afis()
{
    printf("%d\n",rez.size());
    for(vector<int>::iterator it=rez.begin();it!=rez.end();it++)
        printf("%d\n",*it);
}
int main()
{
    read();
    solve();
    init();
    afis();
    return 0;
}