Hiring employees coding interview question

You want to hire some employees. There are N employees in total and each has skill U and wants salary V.

These employees are not independent and have made some groups. Thus, there are Q statements each stating that X and Y belong to the same group. If you want to hire a person then, his entire group must be hired. You have a budget B, you want to hire employees such that you get the maximum possible skill within the budget.

Input Format:

First-line contains T, the number of test cases. Each test case has: First an integer N to denote the number of skills and their salary V Next N lines follow each representing 2 integers U and V (skill and salary) Then we have an integer Q denoting the number of queries Q lines follow representing 2 integers X and Y Last line contains an integer denoting budget B Output Format:

Print a single integer representing the maximum number of skills that can be hired by Monk.

Print 0, if no one can be hired

Constraints:

1<=N,Q<=1000 1<=U<=1000 
Sample Input:

2
5
1 1
2 1
3 1
4 1
5 1
2
1 2
2 3
3
7
1 1
2 2 
3 3
4 2
10 12
12 90
5 8
3
1 2
4 12
2 12
100

In the first case we have the following;

Group   # Employees Cost
[1,2,3] 3   3
[4] 1   1
[5] 1   1
Thus, the maximum employees we can choose are 3 for a cost <= 3 (budget is 3)

In the second case:

Group   # Employees Cost
[1,2,4,12]  4   95
[3] 1   3
[10]    1   12
[5] 1   8
The best we can do with a budget of 100 is to pick 5 employees at a cost of 98

Sample input:

3
5
1 1
2 1
3 1
4 1
5 1
2
1 2
2 3
3
8
10 10
3 20
2 40
7 39
8 24
5 23
6 35
4 50  
3
5 7
6 8
5 6 
240
7
1 1
2 2 
3 3
4 2
10 12
12 90
5 8
3
1 2
4 12
2 12
100
Sample Output:

3
7
5
I'm not able to solve it, Any help would be appreciated! Thanks :)

I'm not asking for a direct solution,
can you explain to me the logic, I'm not able to understand the question something like in layman's terms.
and I'm not that good in English though