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 .
def res(l,n):
	l.sort(key=lambda x:x[0])
	ans=[l[0]]
	
	for i in range(1,n):
		
		if ans[-1][1]<l[i][0] :
			ans.append(l[i])
		if ans[-1][1]>l[i][0] and ans[-1][1]<l[i][1]:
			k=ans[-1][1]
			ans=ans[:len(ans)-1]
			ans.append((l[i][0],k))
		if ans[-1][1]>l[i][0] and ans[-1][1]>l[i][1]:
			ans=ans[:len(ans)-1]
			ans.append(l[i])

		

	return len(ans)

	
t=int(raw_input())
while t>0:
	n=int(raw_input())
	l=[]
	for i in range(0,n):
		p,q=raw_input().split()
		ran=(int(p),int(q))
		l.append(ran)
	print res(l,n)
	t-=1