#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];
vector<int>ans2,ans3;
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;
}
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;
			s[i]=0;d[i]=0;
			e[i].clear();
			num[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);
				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])
			{
				dfs(i);
				ans[i]=1;
			}
		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;	
}