#include<bits/stdc++.h>
using namespace std;
const int N=5e5+10;
vector<int>e[N],num[N];
bool vis[N],vis1[N];
int n,m;
int ans[N];
int s[N];
int d[N];
int fa[N];
vector<int>ans2,ans3;
vector<int> e1[N];
void dfs(int now)
{
	//cout<<now<<endl;
	ans[now]=2;
	vis[now]=1;
	int tmp=e[now].size();
	for(int i=0;i<tmp;i++)
		if(!vis[e[now][i]]){
			ans2.push_back(num[now][i]);
			dfs(e[now][i]);
		}
	else
		ans3.push_back(num[now][i]);
	return;
}
bool vis2[N];
bool flag;
queue<int>que;
int ifdag[N];
int find(int x)
{
	if(fa[x]==x)return x;
	return fa[x]=find(fa[x]);
}
int root;
void dfs1(int now)
{
	fa[now]=root;
	if(ifdag[now]) return ;
	vis2[now]=1;
	que.push(now);
	int tmp=e[now].size();
	for(int i=0;i<tmp;i++)
	{
		if(!vis2[e[now][i]]) 
		{
			dfs1(e[now][i]);
			if(flag) return;
		}
		else
		{
		}
	}
	tmp=e1[now].size();
	for(int i=0;i<tmp;i++)
		if(!vis2[e1[now][i]]) 
			flag=false;
	
}
int main()
{
	int T;
	cin>>T;
	while(T--)
	{
		cin>>n>>m;
		ans2.clear();ans3.clear();
		for(int i=1;i<=n;i++){
			vis[i]=0;vis1[i]=0;ans[i]=0;
			vis2[i]=0;
			s[i]=0;d[i]=0;
			e[i].clear();
			num[i].clear();
			ifdag[i]=0;
			fa[i]=i;
			e1[i].clear();
		}
		for(int i=1;i<=m;i++)
		{
			int l,x,r,y;
			cin>>l>>x>>r>>y;
			if(x>y) {
				swap(l,r);
				swap(x,y);
			}
			vis1[l]=vis1[r]=1;
			if(x==2&&y==2)
			{
				ans[l]=ans[r]=2;
				s[l]=1;s[r]=1;
				ans2.push_back(i);
			}
			if(x==1&&y==2)
			{
				e[l].push_back(r);
				num[l].push_back(i);
				e1[r].push_back(l);
				d[r]++;
			}
			if(x==1&&y==1)
				ans3.push_back(i);
		}
		for(int i=1;i<=n;i++){
			if(s[i]&&!vis[i]&&vis1[i])
				dfs(i);
		}
		for(int i=1;i<=n;i++)
			if(d[i]==0&&!vis[i]&&vis1[i])
			{
				dfs(i);
				ans[i]=1;
			}
		for(int i=1;i<=n;i++)
			if(!vis[i]&&vis1[i])
			{
				root=i;
				flag=true;
				dfs1(i);
				if(flag)
				{
				dfs(i);
				ans[i]=1;
				}
				else
				{
					ifdag[i]=1;
				}
			}
		while(!que.empty())
		{
			int now=que.front();que.pop();
			vis2[now]=0;
		}
		for(int i=1;i<=n;i++)
			if(vis1[i])
				ans[i]=max(ans[i],1);
		int ans1=0;
		for(int i=1;i<=n;i++)
		{
			ans1+=ans[i];
			//cout<<ans[i]<<' ';
		}
		cout<<ans1<<endl;
		int tmp=ans3.size();
		for(int i=0;i<tmp;i++)cout<<ans3[i]<<' ';
		tmp=ans2.size();
		for(int i=tmp-1;i>=0;i--)cout<<ans2[i]<<' ';
		cout<<endl;
	}
	return 0;	
}