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

#define NMAX 1007

using namespace std;

int n, m;
int q[NMAX];
vector <int> v[NMAX];
vector <int> Sol;
int dad[NMAX], Cap[NMAX][NMAX], Flux[NMAX][NMAX];
int a[NMAX], b[NMAX], c[NMAX], Viz1[NMAX], Viz2[NMAX];

void bfs(){
    int start = 0, avans = 0;
    q[avans++] = 1;
    while(start < avans && dad[n] == -1){
        int Nod = q[start++];
        for(int i = 0; i < v[Nod].size(); ++i)
            if(dad[v[Nod][i]] == -1 && Cap[Nod][v[Nod][i]] > 0){
                dad[v[Nod][i]] = Nod;
                q[avans++] = v[Nod][i];
            }
    }
}

void dfs(int Viz[], int Nod){
    Viz[Nod] = 1;
    for(int i = 0; i < v[Nod].size(); ++ i)
        if(Viz[v[Nod][i]] == 0 && Cap[Nod][v[Nod][i]])
            dfs(Viz, v[Nod][i]);
}

void dfs2(int Viz[], int Nod){
    Viz[Nod] = 1;
    for(int i = 0; i < v[Nod].size(); ++ i)
        if(Viz[v[Nod][i]] == 0 && Cap[v[Nod][i]][Nod] < Flux[v[Nod][i]][Nod])
            dfs(Viz, v[Nod][i]);
}

int main(){
    freopen("critice.in", "r", stdin);
    freopen("critice.out", "w", stdout);
    scanf("%d %d\n", &n, &m);
    for(int i = 1; i <= m; ++i){
        scanf("%d %d %d\n", &a[i], &b[i], &c[i]);
        if(a[i] > b[i])
            swap(a[i], b[i]);
        v[a[i]].push_back(b[i]);
        v[b[i]].push_back(a[i]);
        Cap[a[i]][b[i]] += c[i];
        Flux[a[i]][b[i]] = c[i];
    }
     while(1){
       memset(dad, -1, sizeof(dad));
       bfs();
       if(dad[n] == -1)
           break;
       for(int i = 1; i <= n; ++ i)
           if(Cap[i][n] && dad[i] != -1){
               int Min = Cap[i][n];
               for (int v = i, u = dad[v]; u > 0; v = u, u = dad[v])
                   Min = min(Min, Cap[u][v]);
               if(! Min)
                   continue;
               Cap[i][n] -= Min;
               Cap[n][i] += Min;
               for (int v = i, u = dad[v]; u >= 0; v = u, u = dad[v]){
                   Cap[u][v] -= Min;
                   Cap[v][u] += Min;
                }
           }
   }
    dfs(Viz1, 1);
    dfs2(Viz2, n);
    for(int i = 1; i <= m; ++ i)
        if(Viz1[a[i]] == 1 && Viz2[b[i]] == 1)
            Sol.push_back(i);
    printf("%d\n", Sol.size());
    for(int i = 0; i < Sol.size(); ++ i)
        printf("%d\n", Sol[i]);
    return 0;
}