#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned ll
#define endl "\n"
#define PII pair<int,int>
const ll INF=0x3f3f3f3f3f3f3f3f;
const int mod=998244353;
const int N=4e5+5;
struct Node{
	int l,r;
}a[N];
void solve(){
	int n; cin>>n;
	for(int i=1;i<=n;i++) cin>>a[i].l>>a[i].r;
	sort(a+1,a+1+n,[&](Node &t1,Node &t2){
		return t1.l<t2.l;
	});
	for(int i=2;i<=n;i++){
		if(a[i].l<=a[i-1].r){
			cout<<i-2<<endl; return;
		} 
	} cout<<n<<endl;
}
int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	int T=1; cin>>T;
    while(T--) solve();
}