#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> PII;
typedef vector<int> VI;
typedef vector<VI> VII;
const int maxn=222222,mod=998244353;
#define all(v) v.begin(),v.end()
#define sz(v) int(v.size())
#define fi first
#define se second
#define PB push_back
#define MP make_pair
#define lson o<<1,l,mid
#define rson o<<1|1,mid+1,r
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define ROF(i,a,b) for(int i=(a);i>=(b);i--)
#define MEM(x,v) memset(x,v,sizeof(x))
inline int read(){
	int x=0;
	bool f=0;char ch=getchar();
	while(ch<'0' || ch>'9') f|=ch=='-',ch=getchar();
	while(ch>='0' && ch<='9') x=x*10+ch-'0',ch=getchar();
	return f?-x:x;
}
int n,mn[maxn],mx[maxn],l[maxn],r[maxn],tmp[maxn],tl,ans[maxn],al;
int seq[maxn],sl,fa[20][maxn];
void clear(){
	tl=al=0;
}
bool check(int x){
	seq[sl=1]=tl+1;
	FOR(i,0,19) fa[i][tl+1]=tl+1;
	ROF(i,tl,0){
		int nxt=mn[i+1],p=lower_bound(seq+1,seq+sl+1,nxt,greater<int>())-seq;
		if(p==sl+1) continue;
		fa[0][i]=seq[p];
		FOR(j,1,19) fa[j][i]=fa[j-1][fa[j-1][i]];
		int now=i;
		FOR(j,0,19) if((x>>j)&1) now=fa[j][now];
		if(now>mx[i]) seq[++sl]=i;
	}
	return seq[sl]==0;
}
void solve(){
	n=read();
	FOR(i,1,n){
		l[i]=read(),r[i]=read();
		tmp[++tl]=l[i];tmp[++tl]=r[i];
	}
	sort(tmp+1,tmp+tl+1);tl=unique(tmp+1,tmp+tl+1)-tmp-1;
	FOR(i,1,n){
		l[i]=lower_bound(tmp+1,tmp+tl+1,l[i])-tmp;
		r[i]=lower_bound(tmp+1,tmp+tl+1,r[i])-tmp;
	}
	FOR(i,0,tl+1) mn[i]=tl+1;
	FOR(i,1,n) mn[l[i]]=min(mn[l[i]],r[i]);
	ROF(i,tl,0) mn[i]=min(mn[i],mn[i+1]);
	FOR(i,0,tl+1) mx[i]=0;
	FOR(i,1,n) mx[l[i]]=max(mx[l[i]],r[i]);
	FOR(i,1,tl+1) mx[i]=max(mx[i],mx[i-1]);
	int L=1,R=n;
	while(L<R){
		int mid=(L+R)>>1;
		if(check(mid)) R=mid;
		else L=mid+1;
	}
	printf("%d ",L);
	check(L);
	int now=0;
	while(true){
		now=fa[0][now];
		if(now==tl+1) break;
		ans[++al]=tmp[now];
	}
	printf("%d ",al);
	FOR(i,1,al) printf("%d ",ans[i]);
	puts("");
	clear();
}
int main(){
	int T=read();
	while(T--) solve();
}