#include "iostream"
#include "cstring"
#include "cstdio"
#include "algorithm"
#include "queue"
#include "vector"
#include "queue"
#include "stack"
#include "ctime"
#include "set"
#include "map"
#include "cmath"
using namespace std;
#define fi first
#define se second
#define vi vector<int>
#define pb push_back
#define eb emplace_back
#define pii pair<int,int>
#define mp make_pair
#define rep( i , a , b ) for( int i = (a) , i##end = b ; i <= i##end ; ++ i )
#define per( i , a , b ) for( int i = (a) , i##end = b ; i >= i##end ; -- i )
#define mem( a ) memset( a , 0 , sizeof (a) )
#define all( x ) x.begin() , x.end()
//#define int long long
typedef long long ll;
const int MAXN = 2e5 + 10;
int n , m;
pii A[MAXN];
void solve() {
	cin >> n;
	rep( i , 1 , n ) {
		scanf("%d%d",&A[i].fi,&A[i].se);
	}
	sort( A + 1 , A + 1 + n );
	rep( i , 2 , n ) {
		if( A[i].fi <= A[i - 1].se ) {
			printf("%d\n",i - 2); return;
		}
	}
	printf("%d\n",n);
}

signed main() {
//	freopen("in","r",stdin);
//	freopen("out","w",stdout);
	int T;cin >> T;while( T-- ) solve();
//	solve();
}