#include<bits/stdc++.h>
#define rep(i,x,y) for(int i=x;i<=y;i++)
#define per(i,x,y) for(int i=x;i>=y;i--)
using namespace std;
const int N=6e6+10;
const int mod=998244353;
#define int long long
int qmi(int a,int b,int mod){//mod别弄错了
    int res=1;
    for(;b;b>>=1,a=a*a%mod)
        if(b&1)res=res*a%mod;
    return res;
}
void solve() {
    int n;cin>>n;
    vector<array<int,2>>x(n+1);
    rep(i,1,n)cin>>x[i][0]>>x[i][1];
    sort(x.begin()+1,x.end());
    int las=-1,ans=0;
    rep(i,1,n){
        auto [l,r]=x[i];
        if(l<=las){
            cout<<ans<<"\n";
            return;
        }
        else {
            if(i!=1)ans++;
            las=r;
        }
    }
    cout<<ans+1<<"\n";
}
signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int tc = 1;
    cin >> tc;
    for (int i = 1; i <= tc; i++) {
        solve();
    }
}
//2
//3
//1 2
//3 4
//5 6
//3
//1 2
//2 3
//1 5