#include <bits/stdc++.h>
#define pii pair<int, int>
using namespace std;
 
int t,m;
pii d[20010];
vector<int> st;
 
int main() {
	ios::sync_with_stdio(false);
	cin >> t;
	while(t--){
		cin >> m;
		for(int i=0; i<m; i++) cin >> d[i].first >> d[i].second;
		sort(d, d+m);
		st.clear();
		for(int i=m-1; i>=0;i--){
			auto it = upper_bound(st.begin(), st.end(), d[i].second)-st.begin();
			if(it != st.size()){
				st[it] = d[i].second;
			}
			else st.push_back(d[i].second);
		}
		cout << st.size() << endl;
	}
	return 0;
}

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MgozCjEgMQoxIDIKMiAyCjIKMSAxCjEgMg==

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