TJ

#include <bits/stdc++.h>
using namespace std;
struct program{
	int s,e;
}a[1000001];
int n,m;
bool cmp(program aa,program bb)
{
	return aa.e < bb.e;
}
int main()
{
	int t;
	cin>>t;
	while(t--)
	{
		cin>>n;
		for(int i=1;i<=n;i++) cin>>a[i].s>>a[i].e;
		sort(a+1,a+1+n,cmp); 
		int cnt = 1;
		int ans = a[1].e;
		for(int i=2;i<=n;++i)
		{
			if(ans < a[i].s)
			{
				cnt++;
				ans = a[i].e;
			}
		}
		cout<<cnt<<endl;
	}
    return 0;
}