N one dimensional kingdoms are represented as intervals of the form [ai , bi] on the real line.
A kingdom of the form [L, R] can be destroyed completely by placing a bomb at a point x on the real line if L
≤ x ≤ R.


Your task is to determine minimum number of bombs required to destroy all the one dimensional kingdoms.

Input


First line of the input contains T denoting number of test cases.


For each test case, first line contains N denoting the number of one dimensional kingdoms.


For each next N lines, each line contains two space separated integers ai and bi.



Output
For each test case , output an integer denoting the minimum  number of bombs required.

Constraints
Example
Input:
1
3
1 3
2 5
6 9

Output:
2

Explanation
There are three kingdoms [1,3] ,[2,5] and [6,9]. You will need at least 2 bombs
to destroy the kingdoms. In one of the possible solutions, you can place two bombs at x = 2 and x = 6 .
import fileinput

foundT = False
for line in fileinput.input():
    if not foundT:
        foundT = True
        T = int(line)
        first_test_line = True
        continue
    
    if first_test_line:
        first_test_line = False
        N = int(line)
        test_lines_left = N
        start_map = [-1] * 2001
        continue
    
    ai, bi = map(int, line.split())
    start_map[bi] = max(ai, start_map[bi])
    
    test_lines_left += -1
    
    if test_lines_left == 0:
        first_test_line = True
        
        last_bomb = -1
        bomb_count = 0
        for i in range(2001):
            if start_map[i] > last_bomb:
                last_bomb = i
                bomb_count += 1
            
            
        print bomb_count