#P1251D. Salary Changing
Salary Changing
No submission language available for this problem.
Description
You are the head of a large enterprise. people work at you, and is odd (i. e. is not divisible by ).
You have to distribute salaries to your employees. Initially, you have dollars for it, and the -th employee should get a salary from to dollars. You have to distribute salaries in such a way that the median salary is maximum possible.
To find the median of a sequence of odd length, you have to sort it and take the element in the middle position after sorting. For example:
- the median of the sequence is ,
- the median of the sequence is .
It is guaranteed that you have enough money to pay the minimum salary, i.e .
Note that you don't have to spend all your dollars on salaries.
You have to answer test cases.
The first line contains one integer () — the number of test cases.
The first line of each query contains two integers and (, ) — the number of employees and the amount of money you have. The value is not divisible by .
The following lines of each query contain the information about employees. The -th line contains two integers and ().
It is guaranteed that the sum of all over all queries does not exceed .
It is also guaranteed that you have enough money to pay the minimum salary to each employee, i. e. .
For each test case print one integer — the maximum median salary that you can obtain.
Input
The first line contains one integer () — the number of test cases.
The first line of each query contains two integers and (, ) — the number of employees and the amount of money you have. The value is not divisible by .
The following lines of each query contain the information about employees. The -th line contains two integers and ().
It is guaranteed that the sum of all over all queries does not exceed .
It is also guaranteed that you have enough money to pay the minimum salary to each employee, i. e. .
Output
For each test case print one integer — the maximum median salary that you can obtain.
Samples
Note
In the first test case, you can distribute salaries as follows: ( is the salary of the -th employee). Then the median salary is .
In the second test case, you have to pay dollars to the only employee.
In the third test case, you can distribute salaries as follows: . Then the median salary is .