#include <bits/stdc++.h>
#define inf 169696969
using namespace std;
ifstream in("critice.in");
ofstream out("critice.out");
int n,m,graph[1005][1005],daddy[1005];
vector <pair<int,int> > muchii;
vector <int> lista[1005];
deque <int> q;
bool bfs()
{
    memset(daddy,0,sizeof(daddy));
    q.push_back(1);
    daddy[1]=1;
    while(!q.empty())
    {
        int nod=q.front();
        q.pop_front();
        for(auto x:lista[nod])
        {
            if(!daddy[x] && graph[nod][x]>0)
            {
                daddy[x]=nod;
                q.push_back(x);
            }
        }
    }
    return daddy[n];
}
void max_flow()
{
    while(bfs())
    {
        for(auto x:lista[n])
        {
            if(graph[x][n]<=0) continue;
            int flow=graph[x][n];
            for(int u=x; u!=daddy[u]; u=daddy[u])
            {
                int v=daddy[u];
                flow=min(flow,graph[v][u]);
            }
            graph[x][n]-=flow;
            graph[n][x]+=flow;
            for(int u=x; u!=daddy[u]; u=daddy[u])
            {
                int v=daddy[u];
                graph[v][u]-=flow;
                graph[u][v]+=flow;
            }
        }
    }
}
vector <int> sol;
int main()
{
    in >> n >> m;
    for(int i=1; i<=m; i++)
    {
        int x,y,c;
        in >> x >> y >> c;
        muchii.push_back({x,y});
        graph[x][y]=c;
        graph[y][x]=c;
        lista[x].push_back(y);
        lista[y].push_back(x);
    }
    max_flow();
    for(int i=1; i<=m; i++)
    {
        int u=muchii[i-1].first;
        int v=muchii[i-1].second;
        if(graph[u][v] && graph[v][u]) continue;
        graph[u][v]+=69;
        graph[v][u]+=69;
        if(bfs())
        {
            sol.push_back(i);
        }
        graph[u][v]-=69;
        graph[v][u]-=69;
    }
    out << sol.size() << '\n';
    for(auto x:sol)
    {
        out << x << '\n';
    }
    return 0;
}