#include <bits/stdc++.h>
#define N 200011
using namespace std;
vector<int> vv;
struct edge{int u,v,w;};
int dis[N],X,t,n,l[N],r[N];vector<edge> ve;
int F(int w){return w==1?X:w;}
bool BF()
{
	for(int i=0;i<vv.size();++i)dis[i]=0;
	for(int _=0;_<vv.size();++_)
	{
		bool ok=0;
		for(edge e:ve)if(dis[e.v]>dis[e.u]+F(e.w))dis[e.v]=dis[e.u]+F(e.w),ok=1;
		if(!ok)return 1;
	}
	return 0;
}
int main()
{
	scanf("%d",&t);while(t--)
	{
		scanf("%d",&n);vv.clear();ve.clear();
		for(int i=1;i<=n;++i)scanf("%d%d",l+i,r+i),vv.push_back(l[i]-1),vv.push_back(r[i]);
		sort(vv.begin(),vv.end());vv.resize(unique(vv.begin(),vv.end())-vv.begin());
		for(int i=0;i+1<vv.size();++i)ve.push_back({i+1,i,0});
		for(int i=1;i<=n;++i)
		{
			int idl=lower_bound(vv.begin(),vv.end(),l[i]-1)-vv.begin();
			int idr=lower_bound(vv.begin(),vv.end(),r[i])-vv.begin();
			ve.push_back({idr,idl,-1});
			ve.push_back({idl,idr,1});
		}
		int L=1,R=n,ans=0;
		while(L<=R)
		{
			X=L+R>>1;
			if(BF())ans=X,R=X-1;else L=X+1;
		}
		printf("%d ",X=ans);
		BF();
		int mn=1e9;
		for(int i=0;i<vv.size();++i)mn=min(mn,dis[i]);
		printf("%d ",-mn);
		for(int i=1;i<vv.size();++i)if(dis[i]!=dis[i-1])printf("%d ",vv[i]);putchar(10);
	}
	fclose(stdin);fclose(stdout);return 0;
}