#include <bits/stdc++.h>
#define NMAX 1005
#define INF 1e9
using namespace std;

ifstream fin("critice.in");
ofstream fout("critice.out");

struct point{
    int c,f;
};

vector < int > G[NMAX];
vector < pair < int , int > > E;

point F[NMAX][NMAX];
int ant[NMAX];
bool B[NMAX];
bool V[NMAX][2];

inline bool BFS(const int &N){
    int nod;
    memset(B,0,sizeof(B));
    B[1] = 1;
    queue < int > Q;
    Q.push(1);

    while(!Q.empty()){
        nod = Q.front();
        Q.pop();

        for(auto const &it : G[nod]){
            if(B[it] == 1 || F[nod][it].c == F[nod][it].f) continue;

            B[it] = 1;
            ant[it] = nod;
            if(it == N)
                return 1;
            Q.push(it);

        }
    }
    return 0;
}

void DFS(const int &nod,const int &n){
    V[nod][n] = 1;
    for(auto const &it : G[NMAX]){
        if(!V[it][n] && F[nod][it].c > F[nod][it].f){
            DFS(it,n);
        }
    }
}


int main()
{
    ios :: sync_with_stdio(false);
    fin.tie(NULL);

    int n,m,x,y,c,mflow;

    fin >> n >> m;

    for(int i = 1; i <= m; i++){
        fin >> x >> y >> c;

        G[x].push_back(y);
        G[y].push_back(x);
        F[x][y].c = c;
        F[y][x].c = c;
        E.push_back({x,y});

    }



    while(BFS(n)){
        for(auto const &it : G[n]){

            if(B[it] == 0 || F[it][n].c ==  F[it][n].f) continue;

            mflow = INF;
            ant[n] = it;

            for(int j = n; j != 1; j = ant[j])
                mflow = min(mflow,F[ant[j]][j].c - F[ant[j]][j].f);

            if(mflow == 0) continue;

            for(int j = n; j != 1; j = ant[j]){

                F[ant[j]][j].f += mflow;
                F[j][ant[j]].f -= mflow;

            }

        }




    }
    DFS(1,0);
    DFS(n,1);

    int i = 0;
    vector < int > S;
    for(auto const &it : E){
        i++;
        if((F[it.first][it.second].f == F[it.first][it.second].c || F[it.second][it.first].f == F[it.second][it.first].c) && ((V[it.first][0] && V[it.second][1]) || (V[it.second][0] && V[it.first][1]) ))
            S.push_back(i);

    }
    sort(S.begin(),S.end());
    fout << S.size() << "\n";
    for(auto const &it : S)
        fout << it << "\n";

    return 0;
}