#include<fstream>
#include<iostream>
#include<vector>

using namespace std;

int n,sw[1005],C[1000000],t[1005],flux[1005][1006],cap[1006][1006],mc[1005][1006];

vector <int > v[1005],sol;

int bf(int x, int y)
{
	vector<int>:: iterator it;
	int p,u;
	memset(sw,0,sizeof(sw));
	p=u=1;sw[1]=1;
	C[p]=1;
	while(p<=u)
	{
		for (it=v[C[p]].begin();it<v[C[p]].end();++it)
			if (sw[*it]==0 && flux[C[p]][*it]<cap[C[p]][*it])
			{
				sw[*it]=1;
				C[++u]=*it;
			}
		++p;
	}
	
	if (sw[x]==0 || sw[y]==1)
		return 0;
	
	p=u=1;sw[y]=1;
	C[p]=y;
	
	while(p<=u)
	{
		for (it=v[C[p]].begin();it<v[C[p]].end();++it)
			if (sw[*it]==0 && flux[C[p]][*it]<cap[C[p]][*it])
			{
				sw[*it]=1;
				C[++u]=*it;
			}
		++p;
	}
	return sw[n];
}

void critice()
{
	int i,j;
	for (i=1;i<n;i++)
		for (j=i+1;j<=n;j++)
			if (mc[i][j]>0 && flux[i][j]==cap[i][j])
			{
				if (bf(i,j)==1)
					sol.push_back(mc[i][j]);
			}
			else
				if (mc[i][j]>0 && flux[j][i]==cap[j][i])
					if (bf(j,i)==1)
						sol.push_back(mc[i][j]);
}

int maxflux()
{
	vector<int >:: iterator it;
	int s,i,fmax,p,u,k;
	p=u=1;
	C[1]=1;
	memset(sw,0,sizeof(sw));
	sw[1]=1;
	
	while(p<=u)
	{
		for (it=v[C[p]].begin();it<v[C[p]].end();++it)
			if (sw[*it]==0 && cap[C[p]][*it]>flux[C[p]][*it] )
			{
				sw[*it]=1;
				t[*it]=C[p];
				C[++u]=*it;
			}
		++p;
	}
	
	s=0;
	for (i=1;i<n;i++)
		if (sw[i]==1 && cap[i][n]>flux[i][n])
		{
			fmax=cap[i][n]-flux[i][n];
			for (k=i;k>1;k=t[k])
				fmax=min(fmax,cap[t[k]][k]-flux[t[k]][k]);
			flux[i][n]+=fmax;
			for (k=i;k>1;k=t[k])
			{
				flux[t[k]][k]+=fmax;
				flux[k][t[k]]-=fmax;
			}
			s+=fmax;
		}
	return s;
}

void flow()
{
	int i,sol;
	i=1;sol=0;
	while(i!=sol)
	{
		i=sol;
		sol+=maxflux();
	}
}

void afisare()
{
	vector<int> ::iterator it;
	ofstream g("critice.out");
	sort(sol.begin(),sol.end());
	g<<sol.size()<<'\n';
	for (it=sol.begin();it<sol.end();++it)
		g<<*it<<'\n';
	g.close();
}

void citire()
{
	int i,m,x,y,c;
	
	ifstream f("critice.in");
	f>>n>>m;
	
	for (i=1;i<=m;i++)
	{
		f>>x>>y>>c;
		mc[x][y]=mc[y][x]=i;
		cap[x][y]=cap[y][x]=c;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	f.close();
}

int main()
{
	citire();
	flow();
	critice();
	afisare();
	return 0;
}