#include <iostream>
#include <fstream>
#include <bitset>
#include <vector>
#include <queue>

using namespace std;
typedef vector< pair<int, int> >::iterator iter;

#define INF 0x3f3f3f3f
#define MAXN 1005

ifstream f("critice.in");
ofstream g("critice.out");

int n;
int cap[MAXN][MAXN], fl[MAXN][MAXN], t[MAXN];
vector< pair<int, int> > G[MAXN];
bitset<MAXN> viz, vizmuchie, vizmuchie2;
queue<int> q;

bool bfs()
{
    viz.reset();
    viz[0] = true;

    q.push(1);
    while (!q.empty()) {
        int nd = q.front();
        q.pop();

        for (iter it = G[nd].begin(); it != G[nd].end(); it++) {
            if (viz[it->first] == true || cap[nd][it->first] == fl[nd][it->first]) {
                continue;
            }

            viz[it->first] = true;
            t[it->first] = nd;
            q.push(it->first);
        }
    }

    return viz[n];
}

void dfs1(int nd)
{
    for (iter it = G[nd].begin(); it != G[nd].end(); it++) {
        if (vizmuchie[it->second] == true) {
            continue;
        }
        vizmuchie[it->second] = true;

        if (cap[nd][it->first] == fl[nd][it->first]) {
            continue;
        }
        dfs1(it->first);
    }
}

void dfs2(int nd)
{
    for (iter it = G[nd].begin(); it != G[nd].end(); it++) {
        if (vizmuchie2[it->second] == true) {
            continue;
        }
        vizmuchie2[it->second] = true;

        if (cap[it->first][nd] == fl[it->first][nd]) {
            continue;
        }
        dfs2(it->first);
    }
}

int main()
{
    int m;
    f >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y, c;
        f >> x >> y >> c;
        cap[x][y] = c;

        G[x].push_back(make_pair(y, i));
        G[y].push_back(make_pair(x, i));
    }

    while (bfs()) {
        for (iter it = G[n].begin(); it != G[n].end(); it++) {
            if (viz[it->first] == false) {
                continue;
            }
            t[n] = it->first;

            int fmin = INF;
            for (int i = n; i != 1; i = t[i]) {
                fmin = min(fmin, cap[t[i]][i] - fl[t[i]][i]);
            }
            for (int i = n; i != 1; i = t[i]) {
                fl[t[i]][i] += fmin;
            }
        }
    }

    dfs1(1);
    dfs2(n);

    int sol = 0;
    for (int i = 1; i <= m; i++) {
        if (vizmuchie[i] == 1 && vizmuchie2[i] == 1) {
            sol++;
        }
    }

    g << sol << '\n';
    for (int i = 1; i <= m; i++) {
        if (vizmuchie[i] == 1 && vizmuchie2[i] == 1) {
            g << i << '\n';
        }
    }

    f.close();
    g.close();
    return 0;
}