#include<iostream>

 #include<cmath>

 #include<algorithm>

 using namespace std;

 struct wood{

     int l,r;

     int vi;

 }p[];

 int cmp(wood a,wood b)

 {

     if(a.l==b.l)

         return a.r<b.r;

     return  a.l < b.l;

 }

 int main()

 {

     int t; cin >> t;

     while(t--){

         int n;cin >> n;

         for(int i=;i<n;++i){

             cin >> p[i].l >> p[i].r;

             p[i].vi=;

         }

         sort(p,p+n,cmp);        //如果满足 l<=l' and w<=w',则必然满足 l<=l',所以先以它的大小排个序

         int sum,count;

         sum=count=;

         while(count<n){    //    然后反复找

             int kl=-,kr=-;

             for(int i=;i<n;++i){

                 if(p[i].vi&&p[i].l>=kl&&p[i].r>=kr){

                     p[i].vi=;kl=p[i].l;kr=p[i].r;

                     ++count;

                 }

             }

             ++sum;

         }

         cout << sum << endl;

     }

     return ;

 }