You are given a sequence whose term is
You have to evaluate the series
Find .
Input Format
The first line of input contains , the number of test cases.
Each test case consists of one line containing two space-separated integers and .
Output Format
For each test case, print the required answer in a line.
Constraints
Sample Input
3
5 3
4 2
4 1
Sample Output
225
30
10
Explanation
Case 1: We have
Case 2: We have
Case 3: We have