#include<bits/stdc++.h>
using namespace std;
void swap(long long int *p , long long int *q){
long long int temp = *p;
*p = *q;
*q = temp;
}
void sortItMyWay(vector s , vector f){
for(int i=0;i<s.size()-1;i++){
for(int j=0;j<s.size()-1;j++){
if(f[j]>f[j+1]){
swap(&s[j], &s[j+1]);
swap(&f[j] , &f[j+1]);
}
}
}
}
void selectActivity(vector s , vector f){
//cout<<s[0]<<" "<<f[0]<<endl;
int j=0 , count=1;
for(int i=1;i<s.size();i++){
if(s[i]>=f[j]){
//cout<<s[i]<<" "<<f[i]<<endl;
count++;
j=i;
}
}
cout<<count<<endl;
}
int main(){
int t;
cin>>t;
while(t–){
int n;
cin>>n;
vector ti;
vector tf;
for(int i=0;i<n;i++){
int val;
cin>>val;
ti.push_back(val);
cin>>val;
tf.push_back(val);
}
sortItMyWay(ti , tf);
selectActivity(ti,tf);
}
return 0;
}