#include <bits/stdc++.h>

using namespace std;
ifstream in("critice.in");
ofstream out("critice.out");

const int NMAX = 1000;

struct Edge {
    int to, cap, flow, rev;
};

vector<Edge> g[1 + NMAX];
int dist[1 + NMAX], src, dest, n, cap[1 + NMAX][1 + NMAX], rem[1 + NMAX];

void addEdge(int i, int j) {
    Edge a = {j, cap[i][j], 0, g[j].size()};
    Edge b = {i, cap[j][i], 0, g[i].size()};
    g[i].push_back(a);
    g[j].push_back(b);
}

bool bfs() {
    for(int i = 1; i <= n; i ++)
        dist[i] = -1;

    queue<int> q;
    dist[src] = 0;
    q.push(src);

    while(q.size()) {
        int from = q.front();
        q.pop();
        for(auto it : g[from]) {
            if(dist[it.to] == -1 && it.flow < it.cap) {
                dist[it.to] = 1 + dist[from];
                q.push(it.to);
            }
        }
    }

    return (dist[dest] >= 0);
}

int dfs(int from, int deltaflow) {
    if(from == dest)
        return deltaflow;
    for(int i = rem[from]; i < g[from].size(); i ++) {
        Edge &e = g[from][i];
        if(dist[e.to] == dist[from] + 1) {
            int addflow = dfs(e.to, min(deltaflow, e.cap - e.flow));
            if(addflow > 0) {
                Edge &rev = g[e.to][e.rev];
                e.flow += addflow;
                rev.flow -= addflow;
                return addflow;
            }
        }
    }
    return 0;
}

int dinic() {
    int maxflow = 0;
    while(bfs()) {
       for(int i = 1; i <= n; i ++)
            rem[i] = 0;
        int aux = dfs(src, INT_MAX);
        while(aux) {
            maxflow += aux;
            aux = dfs(src, INT_MAX);
        }
    }

    return maxflow;
}

bool visited[1 + NMAX];
vector<int> sol;
int ind[1 + NMAX][1 + NMAX];

int dfs2(int from, int nr) {
    if(from == dest)
        return 1;


    visited[from] = 1;
    int ans = 0;
    for(auto it : g[from]) {
        if(!visited[it.to]) {
            if(it.cap > it.flow)
                ans += dfs2(it.to, nr);
            else if(nr == 0) {
                int aux = dfs2(it.to, nr + 1);
                ans += aux;
                if(aux != 0)
                    sol.push_back(ind[from][it.to]);
            }
        }
    }

    visited[from] = 0;
    return ans;
}

int main() {
    int m;
    in >> n >> m;
    src = 1;
    dest = n;
    for(int i = 1; i <= m; i ++) {
        int x, y, z;
        in >> x >> y >> z;
        cap[x][y] = cap[y][x] = z;
        addEdge(x, y);
        ind[x][y] = ind[y][x] = i;
    }
    int maxflow = dinic();

    out << dfs2(src, 0) << "\n";
    for(auto it : sol)
        out << it << "\n";
    return 0;
}