#include<bits/stdc++.h>
using namespace std;
namespace my_std{
	#define ll long long
	#define bl bool
	ll my_pow(ll a,ll b,ll mod){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res=(res*a)%mod;
			a=(a*a)%mod;
			b>>=1;
		}
		return res;
	}
	ll qpow(ll a,ll b){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res*=a;
			a*=a;
			b>>=1;
		}
		return res;
	}
	#define db double
	#define pf printf
	#define pc putchar
	#define fr(i,x,y) for(register ll i=(x);i<=(y);i++)
	#define pfr(i,x,y) for(register ll i=(x);i>=(y);i--)
	#define go(u) for(ll i=head[u];i;i=e[i].nxt)
	#define enter pc('\n')
	#define space pc(' ')
	#define fir first
	#define sec second
	#define MP make_pair
	#define il inline
	#define inf 1e18
	#define random(x) rand()*rand()%(x)
	#define inv(a,mod) my_pow((a),(mod-2),(mod))
	il ll read(){
		ll sum=0,f=1;
		char ch=0;
		while(!isdigit(ch)){
			if(ch=='-') f=-1;
			ch=getchar();
		}
		while(isdigit(ch)){
			sum=sum*10+(ch^48);
			ch=getchar();
		}
		return sum*f;
	}
	il void write(ll x){
		if(x<0){
			x=-x;
			pc('-');
		}
		if(x>9) write(x/10);
		pc(x%10+'0');
	}
	il void writeln(ll x){
		write(x);
		enter;
	}
	il void writesp(ll x){
		write(x);
		space;
	}
}
using namespace my_std;
vector<pair<ll,ll> > vec[200020];
ll t,n,m,head[200020],cnt=1,d[200020],lf[200020],ans[200020];
bl ck[500050],vis[200020];
struct node{
	ll nxt,to;
}e[1000010];
void add(ll u,ll v){
	e[++cnt].nxt=head[u];
	e[cnt].to=v;
	head[u]=cnt;
}
il ll chk(ll l,ll r){
	if(l<=-1&&-1<=r&&abs(l)%2==1) return -1;
	if(l<=0&&0<=r&&abs(l)%2==0) return 0;
	if(l<=1&&1<=r&&abs(l)%2==1) return 1;
	return inf;
}
il void clr(){
	fr(i,1,n) head[i]=0;
	cnt=1;
	fr(i,1,n) d[i]=lf[i]=ans[i]=vis[i]=0;
	fr(i,1,n) vec[i].clear();
	fr(i,1,m) ck[i]=0;
}
int main(){
	t=read();
	while(t--){
		n=read();
		m=read();
		fr(i,1,m){
			ll u=read(),v=read();
			add(u,v);
			add(v,u);
			d[u]++;
			d[v]++;
		}
		fr(u,1,n){
			if(d[u]!=1) continue;
			go(u){
				ll v=e[i].to;
				lf[v]++;
			}
		}
		fr(j,1,m){
			ll u=e[2*j].to,v=e[2*j+1].to;
			if(d[u]==1||d[v]==1) continue;
			ck[j]=1;
			d[u]--;
			d[v]--;
			bl pd=1;
			if(d[u]==1){
				go(u){
					ll vv=e[i].to;
					if(!ck[i>>1]) lf[vv]++;
					if(lf[vv]>2) pd=0;
				}
			}
			if(d[v]==1){
				go(v){
					ll vv=e[i].to;
					if(!ck[i>>1]) lf[vv]++;
					if(lf[vv]>2) pd=0;
				}
			}
			if(pd) continue;
			if(d[u]==1){
				go(u){
					ll vv=e[i].to;
					if(!ck[i>>1]) lf[vv]--;
				}
			}
			if(d[v]==1){
				go(v){
					ll vv=e[i].to;
					if(!ck[i>>1]) lf[vv]--;
				}
			}
			ck[j]=0;
			d[u]++;
			d[v]++;
		}
		fr(u,1,n){
			if(!lf[u]&&d[u]==2){
				ll x=0,y=0;
				go(u){
					ll v=e[i].to;
					if(ck[i>>1]) continue;
					if(!x) x=v;
					else y=v;
				}
				vec[x].push_back(MP(y,u));
				vec[y].push_back(MP(x,u));
			}
		}
		ll sum=0;
		fr(x,1,n){
			if(vis[x]||!lf[x]) continue;
			vis[x]=1;
			if(lf[x]==1){
				go(x){
					ll v=e[i].to;
					if(ck[i>>1]) continue;
					ans[v]=vis[v]=1;
				}
				continue;
			}
			ll cnt1=0,cnt0=0;
			fr(i,0,(ll)vec[x].size()-1){
				ll v=vec[x][i].fir;
				if(!vis[v]) continue;
				if(ans[v]) cnt1++;
				else cnt0++;
			}
			ll tmp=chk(sum-cnt1-1-cnt0,sum-cnt1-1+cnt0);
			if(tmp!=inf){
				ll tmpsum=tmp;
				tmp=(tmp-(sum-cnt1-1-cnt0))/2;
				sum=tmpsum;
				ans[x]=1;
				fr(i,0,(ll)vec[x].size()-1){
					ll v=vec[x][i].fir;
					if(!vis[v]) continue;
					if(ans[v]) ans[vec[x][i].sec]=0;
					else if(tmp){
						ans[vec[x][i].sec]=1;
						tmp--;
					}
					else ans[vec[x][i].sec]=0;
				}
				go(x){
					ll v=e[i].to;
					if(!ck[i>>1]&&d[v]==1){
						ans[v]=0;
						vis[v]=1;
					}
				}
			}
			else{
				tmp=chk(sum+cnt0+1-cnt1,sum+cnt0+1+cnt1);
				ll tmpsum=tmp;
				tmp=(tmp-(sum+cnt0+1-cnt1))/2;
				sum=tmpsum;
				ans[x]=0;
				fr(i,0,(ll)vec[x].size()-1){
					ll v=vec[x][i].fir;
					if(!vis[v]) continue;
					if(!ans[v]) ans[vec[x][i].sec]=1;
					else if(tmp){
						ans[vec[x][i].sec]=1;
						tmp--;
					}
					else ans[vec[x][i].sec]=0;
				}
				go(x){
					ll v=e[i].to;
					if(!ck[i>>1]&&d[v]==1) ans[v]=vis[v]=1;
				}
			}
		}
		if(sum<=0){
			fr(i,1,n) if(ans[i]) writesp(i);
		}
		else{
			fr(i,1,n) if(!ans[i]) writesp(i);
		}
		enter;
		clr();
	}
}
/*
3
2 1
1 2
6 7
1 2
1 3
2 3
3 4
4 5
4 6
5 6
3 2
1 2
2 3
*/