#include<bits/stdc++.h>
#define poly vector<int>
#define IOS ios::sync_with_stdio(false)
#define ll long long
#define mp make_pair
#define mt make_tuple
#define pa pair < int,int >
#define fi first
#define se second
#define inf 1e18
#define mod 998244353
#define sz(x) ((int)((x).size()))
#define Alls(x) x.begin(),x.end()
// #define int ll
// #define N 
using namespace std;
const int N=300005;
int n,m,l[N],r[N],nxt[N][20];
void BellaKira()
{
    poly g;
    cin>>n;
    for (int i=1;i<=n;i++)
    {
        cin>>l[i]>>r[i];
        g.push_back(l[i]),g.push_back(r[i]);
    }
    g.push_back(-1e9-1);
    sort(Alls(g));
    g.erase(unique(g.begin(),g.end()),g.end());
    m=sz(g);
    for (int i=1;i<=n;i++) l[i]=lower_bound(Alls(g),l[i])-g.begin()+1;
    for (int i=1;i<=n;i++) r[i]=lower_bound(Alls(g),r[i])-g.begin()+1;
    int anst=0;
    poly cst;
    {
        vector<pa>gg;
        for (int i=1;i<=n;i++) 
            gg.push_back(mp(l[i],r[i]));
        sort(gg.begin(),gg.end(),[&](pa x,pa y)
        {
            return x.se<y.se;
        });
        int lst=0;
        for (auto [l,r]:gg)
        {
            if (l>lst) lst=r,anst++,cst.push_back(lst);
        }
        poly s(m+2,0);
        for (auto u:cst) s[u]=1;
        for (int i=1;i<=m;i++) s[i]+=s[i-1];
        anst=0;
        for (auto [l,r]:gg) anst=max(anst,s[r]-s[l-1]);
    }
    // cerr<<"ok"<<" "<<anst<<" "<<sz(cst)<<endl;
    if (anst==1)
    {
        cout<<anst<<" ";
        cout<<sz(cst)<<" ";
        for (auto u:cst) cout<<g[u-1]<<" ";
        cout<<'\n';
        return;
    }
    poly sta;
    poly pre(m+1,0),vaild(m+2,0),Mn(m+1,m+1);
    vaild[m+1]=1;
    sta.push_back(m+1);
    for (int i=1;i<=n;i++)
    {
        pre[l[i]]=max(pre[l[i]],r[i]);
        Mn[l[i]]=min(Mn[l[i]],r[i]);
    }
    for (int i=1;i<=m;i++) pre[i]=max(pre[i],pre[i-1]);
    int mn=m+1;
    for (int i=0;i<=19;i++) nxt[m+1][i]=m+1;
    for (int i=m;i>=1;i--)
    {
        int p=lower_bound(Alls(sta),mn,[&](int x,int y){return x>y;})-sta.begin();
        if (p!=sz(sta))
        {
            nxt[i][0]=sta[p];
            for (int j=1;j<=19;j++) nxt[i][j]=nxt[nxt[i][j-1]][j-1];
            int op=i;
            for (int j=19;j>=0;j--)
                if (((anst-1)>>j)&1) op=nxt[op][j];
            if (op>pre[i]) 
                vaild[i]=1,sta.push_back(i);
        }
        mn=min(mn,Mn[i]);
    }
    if (vaild[1])
    {
        cout<<anst-1<<" ";
        int now=1;
        poly res;
        while (nxt[now][0]<=m)
        {
            now=nxt[now][0];
            res.push_back(now);
        }
        cout<<sz(res)<<" ";
        for (auto u:res) cout<<g[u-1]<<" ";
        cout<<'\n';
    } else
    {
        cout<<anst<<" ";
        cout<<sz(cst)<<" ";
        for (auto u:cst) cout<<g[u-1]<<" ";
        cout<<'\n';
    }
}
signed main()
{
    IOS;
    cin.tie(0);
    int T=1;
    cin>>T;
    while (T--)
    {
        BellaKira();
    }
}
/*list:
1.mod 998244353 or 1e9+7 or ???
2.N
3.duipai shuju xingtai duoyidian
...
*/