#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;

#define Nmax 1001
#define Mmax 10001

int N, M, A[Mmax], B[Mmax], C[Mmax], i;
int T[Nmax], Q[Nmax], F[Nmax][Nmax], st, dr;
vector<int> G[Nmax];

inline int min(int a, int b) { return a<b?a:b; }

int bfs(int nod, int k)
{
    vector<int> :: iterator it;
    
    if (k==1) memset(T, 0, sizeof(T));
    T[ Q[st=dr=0] = nod ] = nod * k;
	
    while ( st<=dr )
	{
        nod = Q[st];
		for (it=G[nod].begin(); it<G[nod].end(); ++it)
			if (!T[*it] && F[nod][*it])
			{
				T[ Q[++dr] = *it ] = nod * k;
				if (Q[dr] == N && k==1) return 1;
			}
		++st;
	}
	
    return 0;
}

void flux()
{
    int nod, m;
     
    while (bfs(1, 1))
    {
        for (nod = N, m = 10000; nod != T[nod]; m = min(m, F[T[nod]][nod]), nod = T[nod]);           
		for (nod = N; nod != T[nod]; F[T[nod]][nod] -= m, F[nod][T[nod]] += m, nod = T[nod]);
	}
}

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", &A[i], &B[i], &C[i]);
        G[A[i]].push_back(B[i]);
        G[B[i]].push_back(A[i]);         
        F[A[i]][B[i]] = F[B[i]][A[i]] = C[i];
    }
    
    flux();
    
    memset(T, 0, sizeof(T));
    bfs(1, 2);
    int aux;
	
    for (i=1; i<=M; ++i)
    {
        aux = F[A[i]][B[i]];
        F[A[i]][B[i]] = F[B[i]][A[i]];
        F[B[i]][A[i]] = aux;
    }
    bfs(N, -1);
	
    int nr=0;
    for (i=1; i<=M; ++i)
        if ( T[A[i]] * T[B[i]] < 0 )
			A[nr++] = i;
	
    printf("%d\n", nr);
    for (i=0; i<nr; ++i)
        printf("%d\n", A[i]);
    
    return 0;
}