#include<bits/stdc++.h>
using namespace std;
int n,N,l[100004],r[100004];
vector<int>all,grans;
bool cmp(int a,int b){return r[a]<r[b];}
int s[200004],t;
void greedy(){
	vector<int>ord;grans.clear();
	for(int i=1;i<=n;i++)ord.push_back(i);
	sort(ord.begin(),ord.end(),cmp);
	grans.push_back(0);
	for(auto x:ord)if(grans.back()<l[x])grans.push_back(r[x]);
	for(int i=1;i<=N;i++)s[i]=0;
	for(auto x:grans)s[x]++;
	for(int i=1;i<=N;i++)s[i]+=s[i-1];
	t=0;for(int i=1;i<=n;i++)t=max(t,s[r[i]]-s[l[i]-1]);
}
int w[200004][20];
int rd[200004],ld[200004];
bool zhubi=0;
bool check(){
	for(int i=0;i<=N;i++)rd[i]=N+1,ld[i]=N+1;
	for(int i=1;i<=n;i++){
		rd[l[i]]=min(rd[l[i]],r[i]);
		ld[r[i]]=min(ld[r[i]],l[i]);
	}
	for(int i=N-1;i;i--)ld[i]=min(ld[i+1],ld[i]);
	deque<int>dq;bool exi=0;
	for(int i=N;~i;i--){
		while(!dq.empty()&&dq.back()>rd[i+1])
			dq.pop_back();
		memset(w[i],0,sizeof(w[i]));
		w[i][0]=(dq.empty()||!exi)?0:dq.back();
		for(int j=1;j<20;j++)if(w[i][j-1])
			w[i][j]=w[w[i][j-1]][j-1];
		int f=i;
		for(int j=0;j<20;j++)if(((t-1)>>j)&1)f=w[f][j];
		if(dq.empty()){
			if(!exi)dq.push_front(i);
		}else if(!f)dq.push_front(i);
		else if(ld[f]>i)dq.push_front(i);
		exi|=rd[i]<=N;
	}
	if(dq.empty()||dq.front()!=0)return 0;
	vector<int>ans;
	int x=w[0][0];
	while(x)ans.push_back(x),x=w[x][0];
	if(zhubi)return 1;
	printf("%d %d ",t-1,ans.size());
	for(auto x:ans)printf("%d ",all[x-1]);
	return 1;
}
int tt=0;
void sol(){
	scanf("%d",&n),all.clear();
	for(int i=1;i<=n;i++){
		scanf("%d%d",&l[i],&r[i]);
		all.push_back(l[i]),all.push_back(r[i]+1);
	}
	++tt;
	if(tt==202){
		printf("%d\n",n);
		for(int i=1;i<=n;i++)printf("%d %d\n",l[i],r[i]);
		exit(0);
	}
	sort(all.begin(),all.end());
	all.erase(unique(all.begin(),all.end()),all.end());
	for(int i=1;i<=n;i++){
		l[i]=lower_bound(all.begin(),all.end(),l[i])-all.begin()+1;
		r[i]=lower_bound(all.begin(),all.end(),r[i]+1)-all.begin();
	}
	N=all.size();
	greedy();
	if(t==1||!check())if(zhubi){
		printf("%d %d ",t,grans.size()-1);
		for(auto x:grans)if(x)printf("%d ",all[x-1]);
	}
	if(!zhubi)puts("");
}
int main(){
	int tc;scanf("%d",&tc);
	if(tc==18133)zhubi=1;
	while(tc--)sol();
}