#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define INF 50000000000009999ll
using ld = long double;
using ull = unsigned long long;
bool cmp(pair<ll,ll> a,pair<ll,ll> b)
{
if(a.first==b.first)
return a.second < b.second;
return a.first < b.second;
}
void solve(vector<pair<ll,ll>> arr,int n)
{
sort(arr.begin(),arr.end(),cmp);
ll cur=arr[0].second,cnt=1;
for(int i=1;i<n;i++)
{
if(arr[i].first >= cur)
{
cur=arr[i].second;
}
else
cnt++;
}
cout<<cnt<<"\n";
}
int main()
{
int t;
cin>>t;
while(t–)
{
int n;
cin>>n;
vector<pair<ll,ll>> arr(n);
for(int i=0;i<n;i++)
cin>>arr[i].first>>arr[i].second;
solve(arr,n);
}
return 0;
}