/**
 *    author:  gary
 *    created: 03.06.2022 20:49:17
**/
#include<bits/stdc++.h>
#define rb(a,b,c) for(int a=b;a<=c;++a)
#define rl(a,b,c) for(int a=b;a>=c;--a)
#define rep(a,b) for(int a=0;a<b;++a)
#define LL long long
#define PB push_back
#define POB pop_back
#define II(a,b) make_pair(a,b)
#define FIR first
#define SEC second
#define SRAND mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define random(a) rng()%a
#define ALL(a) a.begin(),a.end()
#define check_min(a,b) a=min(a,b)
#define check_max(a,b) a=max(a,b)
using namespace std;
const int INF=0x3f3f3f3f;
typedef pair<int,int> mp;
const int MAXN=2e5+10;
int l[MAXN],r[MAXN];
struct BIT{
    int tree[MAXN];
    void clear(){memset(tree,-63,sizeof(tree));}
    void add(int pos,int val){
        while(pos<MAXN){check_max(tree[pos],val);pos+=pos&-pos;}
    }
    int query(int pos){
        int s=0;
        while(pos){
            check_max(s,tree[pos]);
            pos-=pos&-pos;
        }
        return s;
    }
    BIT(){clear();}
};
vector<int> useful;
bool legal[MAXN];
int nxt[MAXN][18];
int minr[MAXN];
int n;
BIT ds;   
bool check(int K){
    fill(legal+1,legal+useful.size()+1,0);
    fill(minr+1,minr+useful.size()+2,INF);
    rb(i,1,n) check_min(minr[l[i]],r[i]);
    rl(i,useful.size()-1,1) check_min(minr[i],minr[i+1]);
    set<int> can;
    rb(i,1,useful.size()+1) ds.tree[i]=-INF;
    rb(i,1,n) ds.add(l[i],r[i]);
    // rb(i,1,n) cout<<l[i]<<" "<<r[i]<<endl;
    rl(i,useful.size(),1){
        if(minr[i+1]==INF){
            nxt[i][0]=0;
        }
        else{
            auto ite=can.upper_bound(minr[i+1]);
            if(ite==can.begin()) continue;
            ite--;
            nxt[i][0]=*ite;
        }
        rb(j,1,17) nxt[i][j]=nxt[nxt[i][j-1]][j-1];
        int now=i;
        rep(j,18) if((K>>j)&1) now=nxt[now][j];
        if(now==0||ds.query(i)<now) legal[i]=1;
        // cout<<i<<" "<<useful[i-1]<<" "<<legal[i]<<" "<<minr[i+1]<<endl;
        if(legal[i]){
            can.insert(i);
        }
    }
    rl(i,minr[1],1) if(legal[i]){
        vector<int> Ans;
        while (i)
        {
            Ans.PB(i);
            i=nxt[i][0];
        }
        cout<<K<<" ";
        cout<<Ans.size()<<" ";
        for(auto it:Ans) cout<<useful[it-1]<<" ";
        cout<<endl;
        return 1;
    }
    return 0;
}
bool cmp(mp A,mp B){
    return A.first!=B.first? A.first>B.first:A.second<B.second;
}
void solve(){
    useful.clear();
    cin>>n;
    rb(i,1,n) cin>>l[i]>>r[i];
    rb(i,1,n) useful.PB(r[i]),useful.PB(l[i]-1);
    sort(ALL(useful));
    useful.erase(unique(ALL(useful)),useful.end());
    rb(i,1,n) l[i]=lower_bound(ALL(useful),l[i])-useful.begin()+1,r[i]=upper_bound(ALL(useful),r[i])-useful.begin();
    vector<mp> seg;
    rb(i,1,n) seg.PB(II(l[i],r[i]));
    int K=0;
    {
        sort(ALL(seg),cmp);
        vector<mp> seg2; 
        int minr=INF;
        for(auto it:seg){
            if(minr<=it.second){
                continue;
            }
            minr=it.second;
            seg2.PB(it);
        }
        vector<int> cho;
        sort(ALL(seg2));
        rep(i,seg2.size()){
            int j=i;
            while (j<seg2.size()&&seg2[j].first<=seg2[i].second)
            {
                j++;
            }
            --j;
            cho.PB(seg2[i].second);
            i=j;
        }
        for(auto it:seg){
            check_max(K,(int)(upper_bound(ALL(cho),it.second)-lower_bound(ALL(cho),it.first)));
        }
    }
    // check(1);
    // return ;
    if(K&&check(K-1)) return;
    check(K);
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int t;
    cin>>t;
    while (t--){
        solve();
    }
    return 0;
}