#include <cstdio>
#include <cstdlib>
#include <vector>
#include <queue>
#include <algorithm>
#include <cstring>
using namespace std;


#define Nmax 1010
#define Inf 0x3f3f3f3f

bool UsedSource[Nmax], UsedSink[Nmax], Used[Nmax];
int N, M, Source, Sink, A[10 * Nmax], B[10 * Nmax], C[10 * Nmax], Ans[10 * Nmax];
vector<int> G[Nmax];
int Cap[Nmax][Nmax], Flow[Nmax][Nmax], Father[Nmax];

void DFS(int Node, bool V[])
{
    V[Node] = 1;
    for(vector<int> :: iterator it = G[Node].begin(); it != G[Node].end(); ++ it)
        if(!V[*it] && Cap[Node][*it] > Flow[Node][*it] && Cap[*it][Node] > Flow[*it][Node])
            DFS(*it, V);
}

bool BFS()
{
    memset(Used, 0, sizeof(Used));
    queue<int> Q;
    Q.push(Source);
    Used[Source] = 1;
    while(!Q.empty())
    {
        int Node = Q.front();
        Q.pop();
        if(Node == Sink) continue;
        for(vector<int> :: iterator it = G[Node].begin(); it != G[Node].end(); ++ it)
            if(!Used[*it] && Cap[Node][*it] > Flow[Node][*it])
            {
                Father[*it] = Node;
                Used[*it] = 1;
                Q.push(*it);
            }
    }
    return Used[Sink];
}

void MaxFlow()
{
    while(BFS())
    {
        for(vector<int> :: iterator it = G[Sink].begin(); it != G[Sink].end(); ++ it)
            if(Used[*it] && Cap[*it][Sink] != Flow[*it][Sink])
            {
                Father[Sink] = *it;
                int MinFlow = Inf;
                for(int Node = Sink; Node != Source; Node = Father[Node])
                    MinFlow = min(MinFlow, Cap[Father[Node]][Node] - Flow[Father[Node]][Node]);
                for(int Node = Sink; Node != Source; Node = Father[Node])
                {
                    Flow[Father[Node]][Node] += MinFlow;
                    Flow[Node][Father[Node]] -= MinFlow;
                }
            }
    }
}

int main()
{
    freopen("critice.in", "r", stdin);
    freopen("critice.out", "w", stdout);
    int i;
    scanf("%i %i", &N, &M);
    Source = 1;
    Sink = N;
    for(i = 1; i <= M; ++ i)
    {
        scanf("%i %i %i", &A[i], &B[i], &C[i]);
        G[A[i]].push_back(B[i]);
        G[B[i]].push_back(A[i]);
        Cap[A[i]][B[i]] = Cap[B[i]][A[i]] = C[i];
    }
    MaxFlow();
    DFS(Source, UsedSource);
    DFS(Sink, UsedSink);
    //Faza e ca, imi trebuie muchiile pt care capacitatea = fluxul
    //Adica un capat sa poata fi vizitat daca plecam din sursa
    //Iar celalalt daca plecam din destinatie
    //Daca muchia curenta ar fi buna, am fi luat drumul cand faceam flux
    //Asa, nu am luat-o si e evident ca trebuie marita capacitatea
    //Pt a putea trimite inca o unitate de flux
    for(i = 1; i <= M; ++ i)
        if((UsedSource[A[i]] && UsedSink[B[i]]) || (UsedSource[B[i]] && UsedSink[A[i]]))
            Ans[++Ans[0]] = i;
    printf("%i\n", Ans[0]);
    for(i = 1; i <= Ans[0]; ++ i)
        printf("%i\n", Ans[i]);
    return 0;
}