#include <bits/stdc++.h>
#define N 200011
using namespace std;
vector<int> vv;int t,n,l[N],r[N],sum[N];
vector<int> vl[N];
int ID(int x){return lower_bound(vv.begin(),vv.end(),x)-vv.begin();}
int main()
{
	scanf("%d",&t);while(t--)
	{
		scanf("%d",&n);vv.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());
		// printf("vv:");for(int x:vv)printf("%d ",x);putchar(10);
		for(int i=0;i<vv.size();++i)vl[i].clear();
		for(int i=1;i<=n;++i)vl[ID(l[i]-1)].push_back(ID(r[i]));
		sum[vv.size()-1]=0;
		for(int i=vv.size()-2;~i;--i)
		{
			sum[i]=sum[i+1];
			for(int r:vl[i])
			{
				// printf("%d<-%d\n",vv[i],vv[r]);
				sum[i]=min(sum[i],sum[r]-1);
			}
		}
		// printf("sum:");for(int i=0;i<vv.size();++i)printf("%d ",sum[i]);putchar(10);
		int x=0;
		for(int i=1;i<=n;++i)x=max(x,sum[ID(r[i])]-sum[ID(l[i]-1)]);
		printf("%d %d ",x,-sum[0]);
		for(int i=1;i<vv.size();++i)if(sum[i]!=sum[i-1])printf("%d ",vv[i]);putchar(10);
	}
	fclose(stdin);fclose(stdout);return 0;
}