Keshi Is Throwing a Party

Description:

Input:

The first line contains a single integer $$$t$$$ $$$(1\le t\le 10^4)$$$ — the number of test cases. The description of the test cases follows.

The first line of each test case contains a single integer $$$n$$$ $$$(1\le n\le 2 \cdot 10^5)$$$ — the number of Keshi's friends.

The $$$i$$$-th of the following $$$n$$$ lines contains two integers $$$a_i$$$ and $$$b_i$$$ $$$(0 \le a_i, b_i < n)$$$.

It is guaranteed that the sum of $$$n$$$ over all test cases doesn't exceed $$$2 \cdot 10^5$$$.

Output:

For each test case print the maximum number of people Keshi can invite.

Sample Input:

3
3
1 2
2 1
1 1
2
0 0
0 1
2
1 0
0 1

Sample Output:

2
1
2

Note:

In the first test case, he invites the first and the second person. If he invites all of them, the third person won't be happy because there will be more than $$$1$$$ person poorer than him.