#include <iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <map>
#include <unordered_map>
#include <set>
#include <cstring>
#include <chrono>
#include <cassert>
#include <bitset>
#include <stack>
#include <queue>
#include <iomanip>
#include <random>
#include <string>
#include <complex>
//#include <ext/pb_ds/assoc_container.hpp>

#ifdef _MSC_VER
#  include <intrin.h>
#  define __builtin_popcount __popcnt
#  define __builtin_popcountll __popcnt64
#endif

#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define x first
#define y second
#define ld long double
#define ll long long
#define ull unsigned long long
#define us unsigned short
#define lsb(x) ((x) & (-(x)))
#define pii pair <int, int>
#define pll pair <ll, ll>

using namespace std;

mt19937_64 gen(time(0));
uniform_int_distribution <int64_t> rng;

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

struct Flow {
    int n;

    int cap[1005][1005];
    int best[1005], lvl[1005];
    bool viz[1005];
    vector <int> g[1005];

    void init(int _n) {
        n = _n;
        memset(cap, 0, sizeof(cap));

        for (int i = 1; i <= n; i++)
            g[i].clear();
    }

    void add_edge(int x, int y, int z) {
        cap[x][y] += z;

        g[x].push_back(y);
        g[y].push_back(x);
    }

    bool bfs(int src, int dst) {
        memset(lvl, 0, sizeof(lvl));
        queue <int> q;

        lvl[src] = 1;
        q.push(src);

        while (!q.empty()) {
            int node = q.front();
            q.pop();

            for (auto& son : g[node]) {
                if (cap[node][son] > 0 && !lvl[son]) {
                    lvl[son] = lvl[node] + 1;
                    q.push(son);
                }
            }
        }

        return lvl[dst] != 0;
    }

    int dfs(int node, int dst, int value = (int)1e9) {
        if (node == dst)
            return value;

        for (auto& son : g[node]) {
            if (cap[node][son] <= 0 || lvl[son] != lvl[node] + 1)
                continue;

            int flow = dfs(son, dst, min(value, cap[node][son]));

            if (flow) {
                cap[node][son] -= flow;
                cap[son][node] += flow;
                return flow;
            }
        }

        return 0;
    }

    int max_flow(int src, int dst) {
        int total_flow = 0, flow;
        while(bfs(src, dst)) {
            while(flow = dfs(src, dst)) {
                total_flow += flow;
                //cout << ops << " " << flow << "\n";
            }
        }

        return total_flow;
    }

    void dfs_reach(int node) {
        viz[node] = 1;
        for (auto& son : g[node]) {
            if (!viz[son] && cap[node][son] > 0)
                dfs_reach(son);
        }
    }
} flow;

int n, m;

void solve(int test) {
    //ld t1 = clock();
    in >> n >> m;
    flow.init(n);
    vector <pii> edges;
    for (; m; m--) {
        int x, y, z;
        in >> x >> y >> z;
        flow.add_edge(x, y, z);
        flow.add_edge(y, x, z);
        edges.push_back({ x, y });
    }

    flow.max_flow(1, n);
    flow.dfs_reach(1);

    vector <int> cut_edges;
    for (int i = 0; i < edges.size(); i++) {
        auto e = edges[i];
        if (flow.viz[e.x] ^ flow.viz[e.y])
            cut_edges.push_back(i + 1);
    }

    out << cut_edges.size() << "\n";
    for (auto& e : cut_edges)
        out << e << "\n";
    //out << (clock() - t1) / CLOCKS_PER_SEC << "s\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    srand(time(0));

    int T = 1;
    //cin >> T;

    for (int t = 1; t <= T; t++) {
        solve(t);
    }

    return 0;
}