#include<bits/stdc++.h>

using namespace std;

#define ll long long

#define A 810000

ll dfn[A],low[A],ver[A],nxt[A],head[A],s[A],fa[A],belong[A],kx[A];

ll Head[A],Nxt[A],Ver[A],To[A],vst[A];

ll tot=0,tot2=0,num=0,n,m,t,root;

vector<ll> dcc[A],ans;

bool cut[A];

void add(ll x,ll y){

    nxt[++tot]=head[x],head[x]=tot,ver[tot]=y;

}

void Add(ll x,ll y){

    Nxt[++tot2]=Head[x],Head[x]=tot2,Ver[tot2]=y;

}

inline ll read(){

    ll f=1,x=0;char c=getchar();

    while(!isdigit(c)){

        if(c=='-') f=-1;

        c=getchar();

    }

    while(isdigit(c)){

        x=(x<<1)+(x<<3)+(c-'0');

        c=getchar();

    }

    return f*x;

}

void tarjan(ll x)

{

    ll flag=0;

    dfn[x]=low[x]=++tot;

    s[++s[0]]=x;

    for(ll i=head[x];i;i=nxt[i])

    {

        ll y=ver[i];

        if(!dfn[y])

        {

            tarjan(y);

            low[x]=min(low[x],low[y]);

            if(low[y]>=dfn[x])

            {

                flag++;

                num++;

                if(flag>1||x!=root)cut[x]=1;

                while(s[0])

                {

                    ll p=s[s[0]--];

                    dcc[num].push_back(p);

                    if(p==y)break;

                }

                dcc[num].push_back(x);

            }

        }

        else low[x]=min(low[x],dfn[y]);

    }

}

void dfs(ll x)

{

    if(x==belong[n])return ;

    vst[x]=1;

    for(ll i=Head[x];i;i=Nxt[i])

    {

        ll y=Ver[i];

        if(vst[y])continue;

        fa[y]=x;

        dfs(y);

    }

    return ;

}

void re(){

    num=0,tot=0;ans.clear();tot2=0;

    for(ll i=0;i<=800000;i++)

        dcc[i].clear();

    memset(nxt,0,sizeof(nxt));

    memset(Head,0,sizeof(Head));

    memset(Nxt,0,sizeof(Nxt));

    memset(fa,0,sizeof(fa));

    memset(vst,0,sizeof(vst));

    memset(head,0,sizeof(head));

    memset(ver,0,sizeof(ver));

    memset(dfn,0,sizeof(dfn));

    memset(low,0,sizeof(low));

    memset(cut,0,sizeof(cut));

    memset(kx,0,sizeof(kx));

}

int main()

{

    t=read();

    while(t--){

        re();

        n=read(),m=read();

        for(ll i=1;i<=m;i++){

            ll x=read(),y=read();

            add(x,y);

            add(y,x);

        }

        for(ll i=1;i<=n;i++)

            if(!dfn[i]) root=i,tarjan(i);

        ll nu=num;

        for(ll i=1;i<=n;i++)

            if(cut[i])belong[i]=++nu,kx[nu]=i;

        for(ll i=1;i<=num;i++)

            for(ll j=0;j<dcc[i].size();j++){

                ll x=dcc[i][j];

                if(cut[x]) Add(belong[x],i),Add(i,belong[x]);

                else belong[x]=i;

            }

/*        for(ll i=1;i<=n;i++){

            cout<<"belong="<<belong[i]<<endl;

        }

*/        dfs(belong[1]);

        ll x=fa[belong[n]];

        while(x!=belong[1]){

            if(x==0) break;

            if(x>num) ans.push_back(kx[x]);

            x=fa[x];

        }

        printf("%lld\n",1ll*ans.size());

        sort(ans.begin(),ans.end());

        for(ll i=0;i<ans.size();i++)

            printf("%lld ",ans[i]);

        cout<<endl;

    }

}