#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>
#include <stdio.h>
using namespace std;


int i,j,n,m,c[1001][1001],viz[1001],cd[1001],f[1001][1001],t[1001],nr,rs[10001];
vector< int > g[1001];
struct muchie{int x,y;}v[10001];

int BFS()
{
	for (int i=1; i<=n; i++) viz[i]=0;
	int st=1,dr=1;
	cd[1]=1;
	while (st<=dr)
	{
		int nod=cd[st++];
		for (size_t k=0; k<g[nod].size(); k++)
		{
			int u=g[nod][k];
			if (c[nod][u]>f[nod][u] && !viz[u])
			{
				viz[u]=1;
				t[u]=nod;
				cd[++dr]=u;
				if (u==n) return 1;
			}
		}
	}
	return 0;
}

int main(){
	
	freopen("critice.in","r",stdin);
	freopen("critice.out","w",stdout);
	
	cin >> n >> m;
	for (i=1; i<=m; i++)
	{
		int x,y,z;
		cin >> x >> y >> z;
		v[i].x=x; v[i].y=y;
		g[x].push_back(y);
		g[y].push_back(x);
		c[x][y]=c[y][x]=z;
	}
	
	while (BFS())
	{
		int fmin=10000000;
		for (j=n; j!=1; j=t[j])
			fmin=min(fmin,c[t[j]][j]-f[t[j]][j]);
		for (j=n; j!=1; j=t[j])
		{
			f[t[j]][j]+=fmin;
			f[j][t[j]]-=fmin;
		}
	}
	
	for (i=1; i<=m; i++)
	{
		c[v[i].x][v[i].y]++; c[v[i].y][v[i].x]++;
		if (BFS()) rs[nr++]=i;
		c[v[i].x][v[i].y]--; c[v[i].y][v[i].x]--;
	}
	
	cout << nr << endl;
	for (i=0; i<nr; i++) cout << rs[i] << endl;

	
	
	return 0;
}