#include<bits/stdc++.h>
using namespace std ;
typedef long long ll ;
typedef unsigned long long ull ;
typedef pair < int , int > pii ;
typedef vector < int > vi ;
#define fi first
#define se second
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()

const int MAXN = 1e5 + 7 ;
const int inf = 1e9 + 7 ;
const int LOG = 20 ;

int n ;
pii a[ MAXN ] ;


int mxcont ;
vector < int > act ;
bool used[ MAXN ] ;

void take_greedy ( ) {
    priority_queue < pii > st , en ;
    for ( int i = 1 ; i <= n ; ++ i ) {
        used[ i ] = false ;
        st.push ( { -a[ i ].fi , i } ) ;
        en.push ( { -a[ i ].se , i } ) ;
    }
    act.clear ( ) ;
    while ( en.empty ( ) == false ) {
        int hh = -inf ;
        while ( en.empty ( ) == false ) {
            auto [ wh , id ] = en.top ( ) ;
            en.pop ( ) ;
            if ( used[ id ] == true ) { continue ; }
            hh = -wh ;
            break ;
        }
        if ( hh == -inf ) { break ; }
        act.push_back ( hh ) ;
        while ( st.empty ( ) == false ) {
            auto [ wh , id ] = st.top ( ) ;
            if ( -wh > hh ) { break ; }
            st.pop ( ) ;
            used[ id ] = true ;
        }
    }
    mxcont = 0 ;
    for ( int i = 1 ; i <= n ; ++ i ) {
        int pos1 = lower_bound ( act.begin ( ) , act.end ( ) , a[ i ].fi ) - act.begin ( ) ;
        int pos2 = upper_bound ( act.begin ( ) , act.end ( ) , a[ i ].se ) - act.begin ( ) ;
        int aux = pos2 - pos1 ;
        mxcont = max ( mxcont , aux ) ;
    }
}

map < int , int > w ;
int rv[ 2 * MAXN ] ;
bool good[ 2 * MAXN ] ;

int lim[ 2 * MAXN ] ;
int nxt[ 2 * MAXN ][ LOG ] ;
vector < int > at_val[ 2 * MAXN ] ;
int mxpref[ 2 * MAXN ] ;
vector < int > ans ;

int foo , tc ;

bool calc ( int sr ) {
    w.clear ( ) ;
    int tp = 0 ;
    for ( int i = 1 ; i <= n ; ++ i ) {
        w[ a[ i ].fi ] = w[ a[ i ].se ] = 0 ;
    }
    for ( auto &e : w ) {
        e.se = ++ tp ;
        rv[ tp ] = e.fi ;
    }
    for ( int i = 0 ; i <= tp + 2 ; ++ i ) {
        at_val[ i ].clear ( ) ;
        good[ i ] = false ;
    }
    for ( int i = 1 ; i <= n ; ++ i ) {
        a[ i ].fi = w[ a[ i ].fi ] ;
        a[ i ].se = w[ a[ i ].se ] ;
        at_val[ a[ i ].fi ].push_back ( a[ i ].se ) ;
    }

    int mn = tp + 1 ;
    for ( int i = tp ; i >= 0 ; -- i ) {
        lim[ i ] = mn ;
        for ( auto en : at_val[ i ] ) {
            mn = min ( mn , en ) ;
        }
    }
    for ( int i = 1 ; i <= tp ; ++ i ) {
        mxpref[ i ] = mxpref[ i - 1 ] ;
        for ( auto x : at_val[ i ] ) {
            mxpref[ i ] = max ( mxpref[ i ] , x ) ;
        }
    }
    good[ tp + 1 ] = true ;
    for ( int i = 0 ; i < LOG ; ++ i ) { nxt[ tp + 1 ][ i ] = tp + 1 ; }
    deque < int > pts ;
    pts.push_back ( tp + 1 ) ;
    for ( int i = tp ; i >= 0 ; -- i ) {
        if ( foo == 18100 && tc == 8630 ) { cout << mxpref[ i ] ; }
        while ( pts.empty ( ) == false && pts.back ( ) > lim[ i ] ) { pts.pop_back ( ) ; }
        if ( pts.empty ( ) == false ) {
            nxt[ i ][ 0 ] = pts.back ( ) ;
            for ( int j = 1 ; j < LOG ; ++ j ) {
                nxt[ i ][ j ] = nxt[ nxt[ i ][ j - 1 ] ][ j - 1 ] ;
            }
            int wh = i ;
            for ( int j = LOG - 1 ; j >= 0 ; -- j ) {
                if ( ( sr & ( 1 << j ) ) > 0 ) { wh = nxt[ wh ][ j ] ; }
            }
            if ( wh > mxpref[ i ] ) {
                good[ i ] = true ;
                pts.push_front ( i ) ;
            }
        }
    }
    if ( good[ 0 ] == false ) { return false ; }
    int x = 0 ;
    ans.clear ( ) ;
    while ( nxt[ x ][ 0 ] <= tp ) {
        ans.push_back ( rv[ nxt[ x ][ 0 ] ] ) ;
        x = nxt[ x ][ 0 ] ;
    }
    return true ;
}



void solve ( ) {
    cin >> n ;
    for ( int i = 1 ; i <= n ; ++ i ) {
        cin >> a[ i ].fi >> a[ i ].se ;
    }
    ++ tc ;
    take_greedy ( ) ;
    if ( calc ( mxcont - 1 ) == true ) {
        cout << mxcont - 1 << " " << ans.size ( ) << " " ;
        for ( auto x : ans ) {
            cout << x << " " ;
        }
        cout << "\n" ;
    }
    else {
        cout << mxcont << " " << act.size ( ) << " " ;
        for ( auto x : act ) {
            cout << x << " " ;
        }
        cout << "\n" ;
    }
}

int main ( ) {
    ios_base :: sync_with_stdio ( false ) ;
    cin.tie ( NULL ) ;
    int t = 1 ; cin >> t ;
    foo = t ;
    while ( t -- ) { solve ( ) ; }
    return 0 ;
}