신입사원

import sys


t = int(sys.stdin.readline())

for _ in range(t):
    n = int(sys.stdin.readline())
    s = sorted([list(map(int, sys.stdin.readline().strip().split())) for _ in range(n)], key=lambda x: x[0])
    
    cnt = 1
    _min = s[0][1]
    for i in range(1, n):
      if s[i][1] < _min:
        _min = s[i][1]
        cnt += 1
    print(cnt)