//练习的结构体和sort排序
#include <algorithm>
#include <iostream>
using namespace std;

struct huiChangtimes {
  int start;
  int end;
};
bool zhengXu(huiChangtimes a, huiChangtimes b) { return a.end < b.end; }
int main() {
  int m = 0;
  cin >> m;
  for (int i = 0; i < m; i++) {
    int n = 0;
    cin >> n;
    huiChangtimes tim[n];
    for (int j = 0; j < n; j++) {
      cin >> tim[j].start >> tim[j].end;
    }
    sort(tim, tim + n, zhengXu);
    int times = 1;
    int lasttimes = tim[0].end;
    for (int j = 1; j < n; j++) {
      if (lasttimes < tim[j].start) {
        times++;
        lasttimes = tim[j].end;
      }
    }
    cout << times << endl;
  }
}