#include <stdio.h>
#include <string.h>
#include <vector>
#include <queue>
using namespace std;
int t2[1005],i,z,fc,fl,c[1005][1005],f[1005][1005],t[1005],n,m;
int x[10005],y[10005];
vector <int> v[1005];
int bf(){
int nod,vec,i;
queue <int> q;
memset(t,0,sizeof(t));
t[1]=-1;
q.push(1);
while(!q.empty())
    {nod=q.front();
    q.pop();
    for(i=0;i<v[nod].size();i++){
        vec=v[nod][i];
        if(!t[vec]&&c[nod][vec]!=f[nod][vec]){
            t[vec]=nod;
            q.push(vec);

        }

    }


    }
if(t[n]) return 1;
return 0;

}
void dinic(){
int i,j,vec;
while(bf())
for(i=0;i<v[n].size();i++){
    vec=v[n][i];
    if(t[vec]&&c[vec][n]!=f[vec][n]){
        fc=c[vec][n]-f[vec][n];
        for(j=vec;j>1;j=t[j])
            fc=min(fc,c[t[j]][j]-f[t[j]][j]);
        if(fc){
            f[vec][n]+=fc;
            f[n][vec]-=fc;
            for(j=vec;j>1;j=t[j]){
                f[t[j]][j]+=fc;
                f[j][t[j]]-=fc;
            }
        //    fl+=fc;
        }

    }

}





}

int main()
{
   freopen("critice.in","r",stdin);
   freopen("critice.out","w",stdout);
scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++){
        scanf("%d%d%d",&x[i],&y[i],&z);
        v[x[i]].push_back(y[i]);
        v[y[i]].push_back(x[i]);
        c[x[i]][y[i]]=z;
        c[y[i]][x[i]]=z;

    }
    dinic();
    bf();
    queue <int> q;
    t2[n]=-1;
    q.push(n);
    while(!q.empty()){
    int nod=q.front();
    q.pop();
    for(i=0;i<v[nod].size();i++){
        int vec=v[nod][i];
        if(!t2[vec]&&c[nod][vec]!=f[nod][vec]&&vec!=n){
            t2[vec]=nod;
            q.push(vec);
        }


    }

    }
    vector <int> sol;
    for(i=1;i<=m;i++){
        if((t[x[i]]&&t2[y[i]]&&c[x[i]][y[i]]==f[x[i]][y[i]])||(t[y[i]]&&t2[x[i]]&&c[y[i]][x[i]]==f[y[i]][x[i]]))
        sol.push_back(i);

    }

    printf("%d\n",sol.size());
//    sort(sol+1,sol+sol.size()+1);
    for(i=0;i<sol.size();i++) printf("%d\n",sol[i]);

   return 0;
}