#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#include<queue>
#include <set>
using namespace std;
int cap[1005][1005];
int flow[1005][1005];
struct Muchii
{
    int y,ind;
};
vector<Muchii> g[1005];
int parcbfs[1005];
queue<int> q;
bool viz[1005];
set<int> s;
bool bfs(int x, int y)
{
    int i;
    q.push(x);
    for(i=1; i<=y; i++)
        viz[i]=0;
    viz[x]=1;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        if(u!=y)
            for(i=0; i<g[u].size(); i++){
                int v=g[u][i].y;
                if(viz[v]==0 && flow[u][v]<cap[u][v]){
                    viz[v]=1;
                    q.push(v);
                    parcbfs[v]=u;
                }
            }
    }
    return viz[y]==1;
}
void detflow(int n){
    int i,flu,maxflow=0;
    while(bfs(1, n)){
        for(i=0; i<g[n].size(); i++){
            int v=g[n][i].y;
            if(cap[v][n]>flow[v][n]){
                parcbfs[n]=v;
                flu=2000000000;
                for(int nod=n; nod!=1; nod=parcbfs[nod])
                    flu=min(flu, cap[parcbfs[nod]][nod]-flow[parcbfs[nod]][nod]);
                for(int nod=n; nod!=1; nod=parcbfs[nod]){
                    flow[parcbfs[nod]][nod]+=flu;
                    flow[nod][parcbfs[nod]]-=flu;
                }
                maxflow+=flu;
            }
        }
    }
}
int main()
{   freopen("critice.in", "r", stdin);
    freopen("critice.out", "w", stdout);
    int n,m,i,x,y,z,j;
    scanf("%d%d", &n, &m);
    for(i=1; i<=m; i++){
        scanf("%d%d%d", &x, &y, &z);
        cap[x][y]=z;
        cap[y][x]=z;
        g[x].push_back({y, i});
        g[y].push_back({x, i});
    }
    detflow(n);
    bfs(1, n);
    for(i=1; i<=n; i++)
        for(j=0; j<g[i].size(); j++)
            if(viz[i]!=viz[g[i][j].y])
                s.insert(g[i][j].ind);
    printf("%d\n", s.size());
    for(set<int>::iterator it=s.begin(); it!=s.end(); it++)
        printf("%d\n", *it);
    return 0;
}