#include <bits/stdc++.h>
#define N 1005
using namespace std;
ifstream in("critice.in");
ofstream out("critice.out");
int n,m,graph[N][N],pater[N],v[N],flow[N][N];
struct edge{
    int x;
    int y;
};
edge lop[5*N];
vector <int> lista[N];
deque <int> q;
bool BFS(int node)
{
    memset(pater,-1,sizeof(pater));
    pater[node]=0;
    q.push_back(node);
    while(!q.empty())
    {
        int p=q.front();
        q.pop_front();
        for(auto x:lista[p])
        {
            if(pater[x]==-1 && graph[p][x]>flow[p][x])
            {
                pater[x]=p;
                q.push_back(x);
            }
        }
    }
    if(pater[n]!=-1)
        return true;
    return false;
}
int main()
{
    in >> n >> m;
    for(int i=1; i<=m;i++)
    {
        in >> lop[i].x >> lop[i].y;
        in >> graph[lop[i].x][lop[i].y];
        graph[lop[i].y][lop[i].x]=graph[lop[i].x][lop[i].y];
        lista[lop[i].x].push_back(lop[i].y);
        lista[lop[i].y].push_back(lop[i].x);
    }
    while(BFS(1))
    {
        for(auto x:lista[n])
        {
            if(x==-1)continue;
            int path=graph[x][n]-flow[x][n];
            for(int i=x; i!=1; i=pater[i])
            {
                int u=pater[i];
                path=min(path,graph[u][i]-flow[u][i]);
            }
            flow[x][n]+=path;
            flow[n][x]=flow[x][n];
            for(int i=x; i!=1; i=pater[i])
            {
                int u=pater[i];
                flow[u][i]+=path;
                flow[i][u]=flow[u][i];
            }
        }
    }
    int nr=0;
    for(int i=1; i<=m; i++)
    {
        graph[lop[i].x][lop[i].y]++;
        graph[lop[i].y][lop[i].x]++;
        if(BFS(1))
        {
            v[++nr]=i;
        }
        graph[lop[i].x][lop[i].y]--;
        graph[lop[i].y][lop[i].x]--;
    }
    out << nr << '\n';
    for(int i=1; i<=nr; i++)
        out << v[i] <<'\n';
    return 0;
}