#include<bits/stdc++.h>
using namespace std;
const int N=5e5+5;
int T,n,m,p[N],v1[N],bg,ed,ans,du[N];
bool c1[N],c2[N],v2[N],us[N];
queue<int>q;
vector<int>e[N],g[N];
struct node{
	int l,x,r,y;
}a[N];
void add(int x){
	if(!c2[x]){
		c2[x]=true;
		q.push(x);
	}
}
void dfs(int x){
	if(g[x].empty())return;
	int u=g[x].back();
	g[x].pop_back();
	int y=a[u].l^a[u].r^x;
	c2[x]=true,c2[y]=false;
	dfs(y);
	p[ed--]=u;
}
void solve(){
	scanf("%d%d",&n,&m);
	bg=1,ed=m;
	for(int i=1;i<=n;++i)c1[i]=c2[i]=v1[i]=v2[i]=0,e[i].clear();
	for(int i=1,l,x,r,y;i<=m;++i){
		scanf("%d%d%d%d",&l,&x,&r,&y);
		us[i]=false;
		a[i]=node{l,x,r,y};
		c1[l]=c1[r]=true;
		if(x==1&&y==1){
			us[i]=true;
			p[bg++]=i;
			continue;
		}
		if(x==2&&y==2){
			us[i]=true;
			p[ed--]=i;
			add(l),add(r);
			continue;
		}
		if(x==2)v2[l]=true;
		else ++v1[l];
		if(y==2)v2[r]=true;
		else ++v1[r];
		e[l].push_back(i);
		e[r].push_back(i);
	}
	for(int i=1;i<=n;++i)if(v2[i]&&!v1[i])add(i);
	for(int i=1;i<=m;++i)if(!us[i]){
		if(a[i].x==1&&!v2[a[i].l]){
			us[i]=true;
			p[ed--]=i;
			add(a[i].r);
		}
		if(a[i].y==1&&!v2[a[i].r]){
			us[i]=true;
			p[ed--]=i;
			add(a[i].l);
		}
	}
	while(!q.empty()){
		int x=q.front();
		q.pop();
		for(auto v:e[x])if(!us[v]){
			int y=x^a[v].l^a[v].r;
			us[v]=true;
			if((a[v].l==x)^(a[v].x>1)){
				add(y);
				p[ed--]=v;
			}else{
				p[bg++]=v;
				--v1[y];
				if(!v1[y])add(y);
			}
		}
	}
	for(int i=1;i<=m;++i)if(!us[i]){
		if(a[i].x==2)++du[a[i].l],--du[a[i].r];
		else ++du[a[i].r],--du[a[i].l];
	}
	for(int i=1;i<=m;++i)if(!us[i]){
		if(a[i].x==2){
			if(du[a[i].l]>0&&du[a[i].r]<0)--du[a[i].l],++du[a[i].r],p[bg++]=i;
			else g[a[i].l].push_back(i);
		}
		else{
			if(du[a[i].r]>0&&du[a[i].l]<0)--du[a[i].r],++du[a[i].l],p[bg++]=i;
			else g[a[i].r].push_back(i);
		}
	}
	for(int i=1;i<=n;++i)if(!g[i].empty())dfs(i);
	ans=0;
	for(int i=1;i<=n;++i){
		if(c1[i])++ans;
		if(c2[i])++ans;
	}
	printf("%d\n",ans);
	for(int i=1;i<=m;++i)printf("%d%c",p[i]," \n"[i==m]);
}
int main(){
	scanf("%d",&T);
	while(T--)solve();
	return 0;
}