#include <cstdio>
#include <vector>
#include <queue>
#include <algorithm>
#include <cstring>

using namespace std;

vector<int> v[1010];
pair<int,int> muchie[10010];
queue<int> q;
int tata[1010],c[1010][1010],flow[1010][1010],sol[10010],n,m;
char vaz[1010],vaz1[1010];

int bfs()
{
    memset(vaz,0,sizeof(vaz));
    q.push(1);
    vaz[1]=1;
    while(!q.empty())
    {
        int nod=q.front();q.pop();
        for(vector<int>::iterator it=v[nod].begin();it!=v[nod].end();it++)
            if(!vaz[*it] && c[nod][*it]<flow[nod][*it])
            {
                vaz[*it]=1;
                tata[*it]=nod;
                q.push(*it);
            }
    }
    return vaz[n];
}

void bfs1()
{
    q.push(n);
    vaz1[n]=1;
    while(!q.empty())
    {
        int nod=q.front();q.pop();
        for(vector<int>::iterator it=v[nod].begin();it!=v[nod].end();it++)
            if(!vaz1[*it] && c[nod][*it]>-flow[nod][*it])
            {
                vaz1[*it]=1;
                q.push(*it);
            }
    }
}

int main()
{
    freopen("critice.in", "r", stdin);
    freopen("critice.out", "w", stdout);
    scanf("%d%d",&n,&m);
    int x,y,s;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x,&y,&s);
        muchie[i]=make_pair(x,y);
        v[x].push_back(y);
        v[y].push_back(x);
        c[x][y]=c[y][x]=s;
    }
    while(bfs())
    {
        for(vector<int>::iterator it=v[n].begin();it!=v[n].end();it++)
            if(vaz[*it] && c[*it][n]>flow[*it][n])
            {
                tata[n]=*it;
                s=1000000;
                for(int i=n;i!=1;i=tata[i]) s=min(s,c[tata[i]][i]-flow[tata[i]][i]);
                for(int i=n;i!=1;i=tata[i])
                {
                    flow[tata[i]][i]+=s;
                    flow[i][tata[i]]-=s;
                }
            }
    }
    x=bfs();
    bfs1();
    int nr=0;
    for(int i=1;i<=m;i++) if((vaz[muchie[i].first] && vaz1[muchie[i].second]) || (vaz1[muchie[i].first] && vaz[muchie[i].second])) sol[++nr]=i;
    printf("%d\n",nr);
    for(int i=1;i<=nr;i++) printf("%d\n",sol[i]);
    return 0;
}