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 .

见题面

见题面