#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define mk make_pair
#define lowbit(x) (x&(-x))
#define pb emplace_back
#define pr pair<int,int>
#define let const auto
#define all(A) A.begin(),A.end()
void chkmin(int &x,int y){x=min(x,y);}
void chkmax(int &x,int y){x=max(x,y);}
const int N=5e5+5;
int read(){
	int x=0,f=1; char c=getchar();
	while(('0'>c||c>'9')&&c!='-') c=getchar();
	if(c=='-') f=0,c=getchar();
	while('0'<=c&&c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return f?x:-x;
}
void solve(){
	vector <int> ans;
	int n=read(),m=read();
	vector <int> vis(n,0),vs(n,0);
	vector <int> both;
	vector <int> fir,Mx(n,0),Mn(n,1);
	vector <vector<pr> > to(n);
	for(int i=1; i<=m; i++){
		int a=read()-1,b=read()-1,c=read()-1,d=read()-1;
		vis[a]=vis[c]=1;
		Mn[a]=min(Mn[a],b);Mn[c]=min(Mn[c],d);
		chkmax(Mx[a],b),chkmax(Mx[c],d);
		if(b&&d){
			vs[a]=vs[c]=1;
			both.pb(i);
		}
		else if(b||d){
			if(b) swap(a,c);
			to[a].pb(c,i);
		}
		else fir.pb(i);
	}
	for(int i=0; i<n; i++) if(!Mx[i])
		for(auto &[u,v]:to[i]) vs[u]=1,both.pb(v);
	queue <int> q;
	for(int i=0; i<n; i++)
		if(vs[i]) q.push(i);
	auto bfs = [&](){
		while(!q.empty()){
			int u=q.front(); q.pop();
			for(auto &[v,id]:to[u]){
				ans.pb(id);
				if(!vs[v]) vs[v]=1,q.push(v);
			}
		}
	};
	bfs();
	int p=0,res=0;
	while(p<n){
		while(p<n&&(vs[p]||Mx[p]==0)) p++;
		if(p>=n) break;
		q.push(p),vs[p]=1;
		bfs();
		p++; res++;
	}
	for(int i=0;i<n;++i)if(Mn[i]==1&&vis[i])--res;
	printf("%d\n",accumulate(all(vis),0)+accumulate(all(vs),0)-res);
	// assert(fir.size()+ans.size()+both.size()==m);
	for(int i:fir) printf("%d ",i);
	reverse(ans.begin(),ans.end());
	for(int i:ans)
		printf("%d ",i);
	for(int i:both)
		printf("%d ",i);
	puts("");
}
int main(){
	int T=read();
	while(T--) solve();
	return 0;
}